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The Datafile PD-CD 1 Issue 2
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PDCD-1 - Issue 02.iso
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utilities
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!RPNCalc
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!Help
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->!Help
RPN Scientific Calculator
=========================
This disc contains a powerful Scientific Calculator using Reverse Polish
Notation for RISC OS on the Archimedes.
The contents of this disc, are as follows;
!Boot *Run by the Filer when it first displays the RPNCalc
directory.
!Sprites Passed to *IconSprites by the !Boot file.
!Run *Run by the Filer when a user double-clicks on the RPNCalc
directory.
!RunImage RPNCalc executable code.
Templates Window templates.
Sprites RPNCalc private sprite file.
Messages Text messages.
!Help Information about RPNCalc.
Choices User choices.
Memory Requirements
===================
Program Area 128K
Limitations
===========
RPNCalc only works under RISC OS 3.10 or greater.
1.0 Getting Started
===================
To copy this application onto another disc, or install it on the hard disc,
open a directory display on the destination disc within the RISC OS Desktop
and drag the !RPNCalc application icon to the destination directory in the
normal manner.
The calculator may be installed on the icon bar by double clicking on the
!RPNCalc application icon.
Double-clicking on the !RPNCalc icon on the icon bar then causes the main
calculator window to be displayed. This implements the numerical keyboard,
display and simple arithmetic functions of the calculator.
Further functions may be accessed through the pop-up menu associated with
the calculator window.
The calculator window may be removed from the screen area in the normal way
by clicking on the close icon. The icon remains on the icon bar and the
calculator's state and registers are maintained.
Choice of the 'quit' item on the icon bar menu causes !RPNCalc to close all
its windows and quit.
RPNCalc is fully compatible with the !Help application.
2.0 Introduction
================
This calculator uses a unique operating logic based on that pioneered in the
handheld calculator market by Clive Sinclair and for many years the basis of
operation for the Hewlett-Packard range of calculators beloved by scientists
and engineers.
This differs from the logic used in most other calculators and centres
around use of the ENTER button. This makes nested and complicated
calculations easier and faster to work out.
For example consider arithmetic functions. To perform arithmetic, key in the
first number, click on ENTER to separate the first number from the second,
then key in the second number and click on '+', '-', '*', or '/'. The result
then appears immediately on the display.
Try the following examples for yourself.
To Compute: Buttons pressed Display
9 - 6 = 3 '9' 'ENTER' '6' '-' 3.00
9 x 6 = 54 '9' 'ENTER' '6' '*' 54.00
9 / 6 = 1.5 '9' 'ENTER' '6' '/' 1.50
3.0 Basic Operation
===================
The calculator supports the entry of numbers and the operation of simple
arithmetic functions through the clicking of the Select button on icons
displayed within the main calculator window.
The icons 0 to 9 and . allow numbers to be entered into the display.
The icons + - / and * cause the corresponding arithmetical operations to be
actioned.
The ENTER icon terminates entry of a number.
The CLR icon allows numbers to be deleted from the display. During number
entry clicking on the CLR icon causes the last digit entered to be deleted.
After number entry has been terminated clicking on CLR causes the entered
number to be cleared.
The CHS icon allows the sign of the displayed number to be changed.
The EXP icon allows exponents to be entered. First enter the mantissa, then
click on EXP and enter the exponent. For a negative exponent click on CHS
after entering the exponent.
The STO and RCL icons allow operation with the 10 internal storage
registers.
The x▓ icon calculates the square of the number in the display.
The 1/x icon calculates the reciprocal of the number in the display.
Further functions may be operated by clicking of the Adjust button on the
icons in the main calculator window.
The + icon accumulates statistical information within the storage registers
R2 through R7.
The - icon allows data to be removed from the accumulated statistical
information.
The ENTER icon rolls the memory stack down.
The CLR icon causes the entire number in the display to be cleared.
The x▓ icon calculates the square root of the number in the display.
The Archimedes keyboard can also be used to control the calculator when the
calculator has the input focus:
The numeric keys 0 to 9 and . allow numbers to be entered into the
display.
The keys + - / and * cause the corresponding arithmetical operations
to be actioned.
Enter and Return have the same action as the 'ENTER' key on the
calculator.
The up and down arrow keys cause the register stack to roll up and down
respectively.
The pop-up menu provides access to more complex functions.
The Function menu option provides access to simple one and two number
arithmetic functions.
The Effect menu option allows control of the display and trigonometric
modes.
The Utilities menu option provides access to transcendental, statistical
and conversion functions as well as a range of constants.
3.1 Icon Bar Menu
=================
Pressing Menu over the RPNCalc icon on the icon bar calls up the RPNCalc
icon bar menu in the normal manner, this contains the following three items.
Info details information about the program
Choices allows the user to set choices that may be preserved from one
use of RPNCalc to the next. The choices available are described in more
detail in the following section.
Quit causes the calculator windows to be closed and the dynamic memory
to be freed.
3.2 User Choices
================
The Choices dialogue box is displayed by clicking on the Choices item in the
icon bar menu and provides the following options.
Register Display:-
The Memory Stack Option causes the four memory stack registers to be
displayed in a window. This allows the operation of the stack to be
observed during use of the calculator.
The Storage Option causes the ten internal storage registers to be
displayed in a window. This allows operations between the calculator
display and storage registers to be achieved by use of the Wimp's drag
and drop features.
The Startup Option causes the calculator and chosen register windows to be
displayed immediately when RPNCalc is installed on the icon bar.
Save saves the choices in the Choices file to be reused in subsequent
sessions and implements the choices immediately.
Cancel reset the choices in use before the dialogue box was displayed.
Set implements the choices for the current session.
3.3 Import and Export of Values
===============================
Results from the display and the displayed storage registers can be
exchanged with other application windows using the drag and drop features of
the WIMP.
3.3.1 Import
A value can be entered into the calculator by dropping the sprite for a
selected save of numerical text from another application into the calculator
display or a displayed storage register.
If the sprite is dropped over the display then the dragged text will be
entered into the calculator as though it has been typed in at the keyboard.
If the sprite is dropped over a storage register then the value is entered
into the register as though it had been entered into the display and then
stored in the register.
3.3.2 Export
The value from the display may be transferred to another application by
pressing select over the display, dragging the resulting sprite to the
intended window and releasing select.
The value from a storage register may also be transferred by pressing Select
over the required storage register in the storage register window, dragging
the resulting sprite to the intended window and releasing Select.
RPNCalc then attempts to place the text icon in the intended window and
insert the text string corresponding to the dragged value.
3.3.3 Calculation
The calculator can also accept input from a text file. This may include both
values and functions.
These will be entered into the calculator as though entered through the
calculator window or computer keyboard.
A carriage return actions the ENTER functions and the simple arithmetic
functions, '-', '+', 'x', and '/' are supported.
For example, if an ASCII text file is prepared with the contents,
1.25
2.5
+
and the file is dragged to the calculator window then both numbers will be
entered into the calculator and the '+' operation executed to give result,
3.75
4.0 Numeric Functions
=====================
This section discusses the numeric functions of RPNCalc available from the
pop-up menu. Several of these functions are also available using the
calculator icons or the computer's keyboard.
4.1 Constants
-------------
The choice of UtilitiesëConstants causes the Physical Constants dialogue box
to be displayed, this contains a vertical list of common physical constants.
Choice of an item from the list causes the chosen constant to be entered
into the calculator.
4.2 Number Alteration Functions
-------------------------------
UtilitiesëAlterationëInteger replaces the number in the display with the
nearest integer of lesser or equal magnitude.
UtilitiesëAlterationëFraction replaces the number in the display with its
fractional part (the difference between the number and its integer part).
UtilitiesëAlterationëRound rounds all 18 internally held digits of the
mantissa of the displayed value to the number of digits specified by the
current display format.
UtilitiesëAlterationëAbsolute yields the absolute value of the number in the
display.
4.3.0 One-Number Functions
--------------------------
4.3.1 General Functions
Choice of the option Functionsë1/x calculates the reciprocal of the number
in the display.
Choice of the option Functionsëx! calculates the factorial of the displayed
value, where x is an integer between 0 and 69.
x! can also be used to calculate the Gamma function, in this case x is not
restricted to non-negative numbers. x! actually calculates Gamma( x+1 ).
Choice of the option Functionsësqrt x calculates the positive square root of
the number in the display.
Choice of the option Functionsëx▓ calculates the square of the number in the
display.
4.3.2 Trigonometric Operations
4.3.2.1 Trigonometric Modes
The trigonometric functions operate in trigonometric modes selected by the
user. The trigonometric mode tells the calculator what unit of measure
(degrees, radians or grads) to assign a number for a trigonometric
function.
Choice of the EffectëMode pop-up menu option causes the trigonometric mode
dialogue box to be displayed allowing the mode to be applied to the
calculator.
Degrees sets Degrees mode. No annunciator appears in the display. This is
the mode on initialisation.
Radians sets Radians mode. The RAD annunciator appears in the display.
Grads sets Grads mode. The GRAD annunciator appears in the display.
4.3.2.2 Trigonometric Functions
Option Chosen Function
UtilitiesëFunctionsëCircularësinh x sine of x
UtilitiesëFunctionsëCircularëasinh x arc sine of x
UtilitiesëFunctionsëCircularëcosh x cosine of x
UtilitiesëFunctionsëCircularëacosh x arc cosine of x
UtilitiesëFunctionsëCircularëtanh x tangent of x
UtilitiesëFunctionsëCircularëatanh x arc tangent of x
Before executing a trigonometric function be sure that the calculator is set
to the desired trigonometric mode.
4.3.3 Time and Angle Conversions
Numbers representing time (hours) or angles (degrees) can be converted by
the calculator between a decimal-fraction and a minutes-second format.
Choice of the UtilitiesëConversionsëH.MS option converts the number in the
display from a decimal format to a minutes-second format.
Choice of the UtilitiesëConversionsëHours option converts the number in the
display from a minutes-second format to a decimal format.
4.3.4 Degrees and Radians Conversions
Number representing angles can be converted between degrees and radians. The
angles must be expressed in decimal numbers and not in minutes-second
format.
Choice of the UtilitiesëConversionsëDegrees option converts the number in
the display to degrees.
Choice of the UtilitiesëConversionsëRadians option converts the number in
the display to radians.
4.3.5 Logarithmic Functions
Choice of the 'UtilitiesëFunctionsëLogarithmicëLN x' option calculates the
natural logarithm of the number in the display; that is, the logarithm to
the base e.
Choice of the 'UtilitiesëFunctionsëLogarithmicëe^x' option calculates the
natural antilogarithm of the number in the display; that is, raises e to the
power of that number.
Choice of the 'UtilitiesëFunctionsëLogarithmicëLOG x' option calculates the
common logarithm of the number in the display; that is, the logarithm to the
base 10.
Choice of the 'UtilitiesëFunctionsëLogarithmicë10^x' option calculates the
common antilogarithm of the number in the display; that is, raises 10 to the
power of that number.
4.3.6 Hyperbolic Functions
Option Chosen Function
UtilitiesëFunctionsëHyperbolicësinh x hyperbolic sine of x
UtilitiesëFunctionsëHyperbolicëasinh x inverse hyperbolic sine of x
UtilitiesëFunctionsëHyperbolicëcosh x hyperbolic cosine of x
UtilitiesëFunctionsëHyperbolicëacosh x inverse hyperbolic cosine of x
UtilitiesëFunctionsëHyperbolicëtanh x hyperbolic tangent of x
UtilitiesëFunctionsëHyperbolicëatanh x inverse hyperbolic tangent of x
4.4.0 Two-Number Functions
--------------------------
The calculator performs two-number functions using two values entered
sequentially into the display. If these numbers are keyed in then they must
be separated by ENTER or any other function that terminates digit entry.
For a two-number function, the first value entered is considered the y-value
because it is placed into the Y-register for memory storage. The second
value entered is considered the x-value because it remains in the display,
which is the X-register.
The arithmetic operators, +, -, * and /, are the four basic two-number
functions. Others are given below.
4.4.1 The Power Function
Choice of the Functionsëy^x option calculates the value of y raised to the x
power. The base number, y, is keyed in before the exponent, x.
4.4.2 Percentages
The percentage functions preserve the value of the original base number
along with the result of the percentage calculation. This allows subsequent
calculations to be carried out using the base number and the result without
re-entering the base number.
4.4.2.1 Percent
Choice of the 'Functionsëx% of y' option calculates the specified
percentage, x, of a base number, y.
4.4.2.2 Percent Difference
Choice of the 'Functionsë(x-y)% of y' option calculates the percent
difference between two numbers. The result expresses the relative increase
(a positive result) or decrease (a negative result) of x compared to y.
4.4.3 Polar and Rectangular Coordinate Conversions
These functions are provided for conversions between polar and rectangular
coordinates.
The angle 'theta' is assumed to be in the units set by the current
trigonometric mode, whether degrees (in decimal format), radians or grads.
4.4.3.1 Polar Conversion
Choice of the UtilitiesëConversionsëPolar option converts a set of
rectangular coordinates (x, y) to polar coordinates (magnitude r, angle
theta). The y-value must be entered first, the x-value second. Upon
execution r will appear in the display. Choose the 'Functionsëx<>y' option
(X exchange Y) to bring theta out of the Y-register and into the display.
Theta will be returned as a value between -180░ and 180░, between -PI and PI
radians, or between -200 and 200 grads.
4.4.3.2 Rectangular Conversion
Choice of the UtilitiesëConversionsëRectangular option converts a set of
polar coordinates (r, theta) to rectangular coordinates (x, y). Theta must
be entered first, then r. Upon execution x will appear in the display.
Choose the 'Functionsëx<>y' option to display y.
5.0 The Automatic Memory Stack and Data Storage
===============================================
5.1 The Automatic Memory Stack and Stack Manipulation
-----------------------------------------------------
The calculator's operating logic is based on a mathematical logic known as
'Polish Notation'. Conventional algebraic notation places the algebraic
operators between the relevant numbers or variables when evaluating
algebraic expressions. 'Polish Notation' specifies the operators before the
variables.
The calculator uses the convention, applied by Hewlett Packard for
efficiency of use, of specifying the operators after the variables. Hence
the term 'Reverse Polish Notation' (RPN).
RPNCalc uses RPN to solve complicated calculations in a straightforward
manner, without parentheses or punctuation. It does so by automatically
retaining and returning intermediate results. This system is implemented
through the automatic memory stack and the ENTER function, minimising total
operations.
The number that appears in the display is the X-register. Any number that is
keyed in or results from the execution of a numeric function is placed into
the display (X-register). This action will cause numbers already in the
stack to lift, remain in the same register, or drop, depending upon both the
immediately preceding and the current operation. Numbers in the stack are
stored on a last-in, first-out basis. For convenience the registers are
named X, Y, Z and T.
The number in the T-register remains there when the stack drops, allowing
this number to be used repetitively as an arithmetic constant.
5.1.1 Stack Display
Selection of the Memory Stack Option in the Choices dialogue box allows the
four stack registers to be displayed in a window.
5.1.2 Stack Manipulation Functions
Clicking on ENTER separates two numbers keyed in one after the other. It
does so by lifting the stack and copying the number in the display
(X-register) into the Y-register. The next number entered then writes over
the value in the X-register; there is no stack lift.
The up and down arrow keys on the computer keyboard roll the contents of the
stack registers up and down one register (one value moves between the X and
the T-register). No values are lost. Clicking of the ADJUST button on the
ENTER icon also rolls the register stack down.
Choice of the Functionsëx<>y pop-up menu option exchanges the numbers in the
X and Y-registers.
5.1.3 The LAST X Register
The LAST X register is a separate memory register which preserves the value
that was last in the display before execution of a numeric operation. Choice
of the 'UtilitiesëLAST X' pop-up menu option places a copy of the contents
of the LAST X register into the display.
The LAST X feature avoids the re-entry of numbers needed again. It can also
assist in error recovery, such as executing the wrong function or keying in
the wrong number.
5.1.4 Calculator Functions and the Stack
When two numbers are entered, one after the other, ENTER is operated between
entries. However ENTER does not need to be used when a number is immediately
followed by a function. This is because most functions enable lifting of the
stack, such that the stack will lift automatically when the next number is
keyed or recalled into the display, and terminates digit entry, so that the
next number starts a new entry.
There are four functions - ENTER, CLx, SUM+ and SUM- - that disable stack
lift. Following execution of one of these functions a new number will write
over the currently displayed number instead of causing the stack to lift.
In most cases the effects are natural.
5.1.5 Order of Entry and the ENTER key
An important aspect of two-number functions is the positioning of the
numbers in the stack. To execute an arithmetic function, the numbers should
be positioned in the stack in the same way that they are vertically
positioned on paper. For example:
98 98 98 98
-15 +15 x15 /15
--- --- --- ---
The first (or top) number would be in the Y-register, while the second (or
bottom) number would be in the X-register. When the mathematical operation
is performed, the stack drops, leaving the result in the X-register.
5.1.6 Nested Calculations
The automatic stack lift and stack drop make it possible to do nested
calculations without using parentheses or storing intermediate results. A
nested calculation is solved simply as a series of one and two-number
operations.
Almost every nested calculation can be done using just the four stack
registers. It is usually wisest to begin the calculation at the innermost
number or pair of parentheses and work outwards (as for a manual
calculation). Otherwise an intermediate result may need to be placed in a
storage register. For example, consider the calculation of
3 ( 4 + 5 ( 6 + 7 ) ) :
Entries Display
6 ENTER 7 + 13.00 Intermediate result of ( 6 + 7 ).
5 x 65.00 Intermediate result of 5 ( 6 + 7 ).
4 + 69.00 Intermediate result of ( 4 + 5 ( 6 + 7 ) ).
3 x 207.00 Final result: 3 ( 4 + 5 ( 6 + 7 ) ).
The stack automatically drops after each two-number calculation, and then
lifts when a new number is keyed in.
5.1.7 Arithmetic Calculations with Constants
There are three ways (without using a storage register) to manipulate the
memory stack to perform repeated calculations with a constant:
1. Use the LAST X register
2. Load the stack with a constant and operate upon different numbers.
3. Load the stack with a constant and operate upon an accumulating
numbers.
5.1.7.1 LAST X
Enter the constant second so that it will be saved in the LAST X register.
Choice of the 'UtilitiesëLAST X' pop-up menu option will place a copy of the
contents of the LAST X register into the X-register (the display). This can
be done repeatedly.
5.1.7.2 Loading the Stack with a Constant
Because the number in the T-register is replicated when the stack drops,
this number can be used as a constant in arithmetic operations.
Fill the stack with a constant by entering it into the display and clicking
on ENTER three times. Enter the initial argument and perform the arithmetic
operation. The stack will drop, a copy of the constant will "fall" into the
Y-register, and a new copy of the constant will be generated in the
T-register.
If the variables change be sure to clear the display before entering the new
variable. This disables the stack so that the arithmetic result will be
written over and only the constant will occupy the rest of the stack.
If the operation is to be performed on a cumulative number, then do not
clear the display - simply repeat the arithmetic operation.
5.2 Storage Register Operations
-------------------------------
When numbers are stored or recalled, they are copied between the display
(X-register) and the data storage registers. RPNCalc has 10 directly
accessible storage registers: R0 through R9. Six registers, R2 to R7, are
also used for statistics calculations.
5.2.1 Storage Register Display
Setting of the Storage Option in the Choices dialogue box allows the ten
storage registers to be displayed in a window.
This allows storage register operations to be performed using the drag and
drop features of the WIMP under RISC OS as well as simplifying the normal
operations.
On the left of each storage register is a radio button, this can be used to
select a storage register. Only one storage register may be selected at any
one time. Pressing Adjust over a selected radio button will deselect it such
that no storage registers are selected. (This is a slight deviation from the
RISC OS 3 Style Guide).
5.2.2 Storing and Recalling Numbers
5.2.2.1 Storing Numbers
Clicking on the STO icon followed by a storage register address (0 through
9) copies the number from the display into the specified data storage
register replacing the existing contents of that register. During this
operation a STO annunciator appears in the display showing that a storage
register address is required.
If the storage register window is open and one of the storage registers has
been selected then clicking on the STO icon will copy the number from the
display into the selected data storage register without entry of the storage
register address.
The number from the display may also be transferred to a storage register by
pressing Select over the display, dragging the resulting sprite to the
required storage register in the storage register window and releasing
Select.
5.2.2.2 Recalling Numbers
Clicking on the RCL icon followed by a storage register address (0 through
9) copies the number from the specified data storage register into the
display. The contents of the storage register remain unaltered. During this
operation a RCL annunciator appears in the display showing that a storage
register address is required.
If the storage register window is open and one of the storage registers has
been selected then clicking on the RCL icon will copy the number from the
selected data storage register into the display without entry of the storage
register address.
The number from a storage register may also be transferred to the display by
pressing Select over the required storage register in the storage register
window, dragging the resulting sprite to the display and releasing Select.
5.2.2.3 Exchanging Numbers
If the storage register window is open then the number from a storage
register may be exchanged with the display by pressing Select over the
required storage register in the storage register window, dragging the
resulting sprite to the display and releasing Select, while the SHIFT key is
pressed.
5.2.3 Clearing Data Storage Registers
This function has not been implemented.
5.2.4 Storage and Recall Arithmetic
5.2.4.1 Storage Arithmetic
It is possible to perform arithmetic on a number in a storage register and
store the result in the same register without use of the RCL operation.
With the second operand in the display click on the STO icon followed by one
of, +, -, x, or /. The STOn annunciator will appear in the display, where n
is one of, +, -, x, or /. Finally key in the register address (0 to 9) by
selecting the corresponding icon.
The new number in the register is determined as follows.
+
new contents = old contents - number in
of register of register x display
/
5.2.4.2 Recall Arithmetic
Recall arithmetic allows arithmetic with the displayed value and a stored
value without lifting the stack, that is, without losing any values from the
Y, Z and T-registers.
With the second operand in the display click on the RCL icon followed by one
of, +, -, x, or /. The RCLn annuncator will appear in the display, where n
is one of, +, -, x, or /. Finally key in the register address (0 to 9) by
selecting the corresponding icon.
The new number in the register is determined as follows.
+
new display = old display - contents of
x register
/
5.2.4.3 Overflow and Underflow
On underflow the calculate reports a 'Divide by zero' error and the register
is unchanged.
6.0 Statistical Functions
=========================
6.1 Probability Calculations
----------------------------
The input for permutation and combination calculations is restricted to
nonnegative integers. Enter the y-value before the x-value. These functions,
like the arithmetic operators, cause the stack to drop as the result is
placed in the X-register.
6.1.1 Permutations
Choice of the UtilitiesëFunctionsëStatisticalëPxy pop-up menu option
calculates the number of different arrangements of y different items taken
in quantities of x items at a time. No item occurs more than once in an
arrangement, and different order of the same x items in an arrangement are
counted separately. The formula is
y!
Py,x = --------
(y - x)!
6.1.2 Combinations
Choice of the UtilitiesëFunctionsëStatisticalëCxy pop-up menu option
calculates the number of possible sets of y different items taken in
quantities of x items at a time. No item occurs more than once in a set, and
different order of the same x items in a set are not counted separately. The
formula is
y!
Cy,x = ----------
x!(y - x)!
6.2 Random Number Generator
---------------------------
Choice of the UtilitiesëFunctionsëStatisticalëRAN# pop-up menu option will
generate a random number in the range 0 <= r < 1.
6.3 Accumulating Statistics
---------------------------
RPNCalc performs one and two-variable statistical calculations through the
use of the SUM+ and SUM- functions.
The SUM+ function is executed by clicking on the + icon with the Adjust
button. Similarly the SUM- function is executed by clicking on the - icon
with the Adjust button.
The data is first entered into the Y and X registers. Then the SUM+ function
automatically calculates and stores statistics of the data in storage
registers R2 through R7. These registers are therefore referred to as the
statistics registers.
Therefore before beginning to accumulate statistics for a new set of data
ensure that the statistics registers and stack are clear.
In one-variable statistical calculations, enter each data point (x-value) by
keying in x and executing SUM+.
In two-variable statistical calculations, enter each data pair (x and
y-values) by keying by first keying in the y-value, clicking on ENTER, then
keying in the x-value, and finally executing SUM+.
The current number of accumulated data points, n, will be displayed. The
x-value is saved in the LAST X register and y remains in the Y-register.
SUM+ disables stack lift, so the stack will not lift when the next number is
keyed in.
The statistics of the data are compiled as follows:
Register Contents
R2 n Number of data points accumulated.
R3 SUMx Summation of x-values.
R4 SUMx▓ Summation of squares of x-values.
R5 SUMy Summation of y-values.
R6 SUMy▓ Summation of squares of y-values.
R7 SUMxy Summation of products of x and y-values.
Any of the accumulated statistics can be recalled to the display by clicking
on RCL and the number of the data storage register containing the desired
statistic.
6.3.1 Correcting Accumulated Statistics
If data is entered incorrectly, the accumulated statistics can be easily
corrected. Key the incorrect data pair into the Y and X-registers and
execute SUM-, then key in the correct value for x and y and execute SUM+.
Alternatively, it the incorrect data point or pair is the most recent one
entered and SUM+ has been pressed, choosing the 'UtilitiesëLAST X' pop-up
menu option and executing SUM- will remove the incorrect data.
6.3.1 Mean
Choice of the UtilitiesëFunctionsëStatisticalëmean pop-up menu option
calculates the arithmetic mean of the x and y values using the statistics
accumulated in the relevant registers, the contents of the stack lift and
the mean of x is copied into the X-register as the mean of y is copied into
the Y-register.
Choice of the 'Functionsëx<>y' pop-up menu option can be used to view the
mean of y if the memory stack registers are not displayed.
6.3.2 Standard Deviation
Choice of the UtilitiesëFunctionsëStatisticalësd pop-up menu option
calculates the standard deviation of the accumulated statistics data.
This function gives an estimate of the population standard deviation from
the sample data, and is therefore termed the sample standard deviation. On
execution the contents of the stack are lifted and the Sx is placed into the
X-register as the Sy is placed into the Y-register.
Choice of the 'Functionsëx<>y' pop-up menu option can be used to view Sy if
the memory stack registers are not displayed.
6.3.3 Linear Regression
This function has not been implemented.
6.3.4 Linear Estimation and Correlation Coefficient
This function has not been implemented.
6.3.5 Other Applications
6.3.5.1 Vector Arithmetic
The statistical accumulation functions can be used to perform vector
addition and subtraction. Polar coordinates must be converted to rectangular
coordinates upon entry. The results are available in R3 (Sum of x) and R5
(Sum of y) and may be converted back to polar coordinates, if necessary.
For the second vector entered, the final function will be either SUM+ or
SUM-, depending on whether the two vectors should be added or subtracted.
7.0 The Display
===============
The calculator has three display formats - fixed decimal, scientific, and
engineering - that may be specified using the Display Format dialogue box
accessible from the EffectsëDisplay pop-up menu option.
The current display format takes affect when digit entry is terminated;
until then, all digits keyed in (up to 16) are displayed.
7.1 Fixed Decimal Display
Fixed decimal format displays a figure with the number of decimal places
specified (up to 10, depending on the size of the integer portion).
Exponents will be displayed if the number is too small or too large for the
display.
7.2 Scientific Notation Display
Scientific format displays a figure in scientific notation with the number
of decimal places specified (up to 10). In this mode exponents are
displayed.
7.3 Engineering Notation Display
Engineering format displays numbers in an engineering notation format in a
manner similar to scientific, except that all exponents are shown in
multiples of three.
7.4 Mantissa
Regardless of the display format the calculator always internally holds each
number as a 18 bit mantissa and a three bit exponent.
8.0 Limits
==========
The calculator performs all internal mathematical calculations using double
precision floating point numbers with limits as defined in the float.h
header of ANSI C Release 4.
9.0 Known Bugs
==============
Engineering mode display is the same as scientific mode.
On the RiscPC the drop and drag functions appear to effect the anti-aliased
fonts used by the WIMP. WIMP test appears to be changes back to the system
font. The screen needs to be refreshed in order to recover the normal font.
Detection of overflow is not good. Overflow can sometimes crash RPNCalc.
=============================================================================
Release 1.00 November 1994
(c) Copyright Peter Tuson 1994
This product is distributed as public domain. It be reproduced in
whole or part by any means without written permission of the author.
While every care is taken, the author cannot be held responsible for
any errors in this product, or for the loss of any data or
consequential effects from the use of this package.
RISC OS, RiscPC and Archimedes are trademarks of Acorn Computer Ltd.
The source for constants and neumeric formulas was obtained from:
Handbook of Mathematical Functions
Edited by Abramowitz and Stegun
published by Dover, SBN 0-486-61272-4
======
If you find this program useful or interesting a donation of ú10 sterling,
sent to the address below, would be much appreciated.
If you have any comments, suggestions, more bug reports or complaints,
please write to the following address. This does not constitute a commitment
to correct reported bugs.
Dr. P.R.Tuson
70, Connaught Road
Fleet
Hants.
GU13 9QY
United Kingdom.