home
***
CD-ROM
|
disk
|
FTP
|
other
***
search
/
Gold Medal Software 5
/
Gold Medal Software - Volume 5 (Gold Medal) (1995).iso
/
accounts
/
sly142ab.arj
/
SLY142A.EXE
/
SIY9.TXT
< prev
next >
Wrap
Text File
|
1994-01-08
|
11KB
|
302 lines
SIY9.TXT Calculators and Computers 48
Chapter 9
Calculators and Computers
For this chapter you will need:
a) A calculator or computer with SIN and COS functions. A Sharp
EL-506A scientific calculator is available for $25 plus $5
shipping & handling from CAVE Inc, 1/2 Fast Road, Ritner, KY
42639. 606/376-3137.
b) Pencil and paper,
c) Graph paper,
d) An understanding of how to plot a map by hand.
You will not need:
a) An assistant,
b) Any special mathematical training.
It is easier, and far more accurate, to calculate rather than to
hand plot a map. But unless you already know how to hand plot,
the mathematics will just be so much magic to you. Magic is fine
for magicians and economists, but magic allows surveyors'
blunders to escape undetected.
This fancy math comes with even fancier qualifications. Firstly,
you can learn this only after you already know how to plot a map
by hand. Secondly, if you have only a small amount of surveying,
you will probably find it easier to hand plot than to learn
this. Thirdly, if you wait until you have an incentive, it will
be a whole lot easier to learn.
To do these calculations, you must have a SIN function on your
calculator. These are usually called scientific calculators. I
prefer a Sharp EL-506A, which does the calculations with one
entry, instead of the double entry needed on most other
scientific calculators. It also does all trigonometric,
logarithmic, power, and inverse functions, as well as calculating
mean and standard deviations. And these do not interfere with
its use as a common calculator. $25 from CAVE, Inc.
SIY9.TXT Calculators and Computers 49
A programmable calculator is nice if you know how to program it.
I personally have used a 1980 model Radio Shack BC-4000
programmable calculator made by Texas Instruments. It has eight
addressable internal memories and fifty program steps. I can
calculate everything that I want to know without writing down any
intermediate data. If you use a calculator without addressable
memories, then you will have to use paper and pencil for memory.
It's a whole lot easier to learn with the paper and pencil, too.
This sort of programmable calculator costs about $40.
I have also used an assortment of computers. Those computers
which I have programmed and which are still on the market at a
reasonable price are: Commodore VIC-20, Radio Shack COCO 2, Radio
Shack TRS-80 III, Apple //e, Laser 128 (an Apple //c clone), and
several varieties of the ibm [service mark of Imperious Behemoth
Machinations, Inc] PC clone. A computer is easier to use than a
programmable calculator, but you can't take it into the field
with you to calculate while you survey. Even if you have a
notebook computer, I doubt that you would take it into the field.
A table of data is needed to record and calculate the station
locations. Label a sheet of paper with the following headings:
TO FROM COMP TAPE RUN INORTH IEAST SNORTH SEAST Comments
The first four columns are the raw data taken from the field.
For practice, copy the values from Table 1.
RUN is the total distance so far. RUN (of the TO station) is
RUN (of the FROM station) plus TAPE.
INORTH is the incremental distance north for this shot. INORTH
is TAPE times the cosine of COMP. IEAST is the incremental
distance east for this shot. IEAST is TAPE times the sine of
COMP.
SNORTH is the summation distance north of wherever you started.
SNORTH (TO) is SNORTH (FROM) plus INORTH. SEAST is the summation
distance east of where ever you started. SEAST (TO) is SEAST
(FROM) plus IEAST.
Be sure to keep your pluses and minuses straight. Negative NORTH
is south. Negative EAST is west. Don't blunder.
SIY9.TXT Calculators and Computers 50
To plot your map, use SNORTH and SEAST to plot the location of
each station on a piece of graph paper. Start with a clean sheet
of graph paper. Draw a North Arrow.
Pick a map scale. You can use any map scale here with no loss of
precision. For now, chose the same scale as you used to plot
your very first map, 100 feet per inch.
Pick a place to start. From point 0, draw a line north. Along
this north axis, label the distance every 100 feet. Draw and
label the east axis. South and west too.
Plot the location of station 0. SNORTH is 0 units north of where
ever you called 0. Put a dot on the north axis at 0. SEAST is 0
units east of where ever you called 0. Move the dot which you
just put on the north axis to 0 units east. Sounds kinda silly,
but 0 is not a special case.
Plot the location of station 1 the same way. SNORTH is 153. Put
a dot on the north axis 153 hundredths of an inch north of 0.
SEAST is 129. Move the dot (maybe it's easier to leave it and
make a new dot?) to 129 hundredths of an inch east. That's the
location of station 1. That should be the same place as when you
located the station the old way, back in Chapter 1. Now you know
how you will check your work while learning all these new things.
Plot the rest of the stations from the data of Table 1. If you
draw lines between the stations, this map should look just like
the one which you plotted on Graph 1.
You'll have to decide which method to use. Plotting with the
Ranger is quick to learn and the map can be drawn in the field as
a blunder trap. The calculator is faster and more accurate,
especially on long surveys. You'll know when it becomes easier
to use a calculator.
If you are using inclination, a lengthier table is needed:
TO FROM COMP TAPE INCL HDIST RUN INORTH IEAST IUP
SNORTH SEAST SUP
SIY9.TXT Calculators and Computers 51
To correct the measured distance to a true horizontal distance,
multiply the distance times the cosine of the inclination. HDIST
is TAPE times the cosine of INCL. IUP is the incremental
distance up in this shot. IUP is TAPE multiplied times the sine
of INCL. SUP is the summation up (elevation) of the station
above the starting station. SUP(TO) is SUP(FROM) plus IUP.
Negative UP is down.
So now you have SUP. What do you do with it? Unless you are
plotting 3-D maze caves on 3-D graph paper, you can probably just
ignore it. Write in the elevation as necessary. You can also
plot a graph using SUP and SNORTH as the axes. This is called a
cross section. You could also plot SUP and SEAST. There is a
lot more fancy mathematics which can be done, but I doubt many of
you will be interested in even this much. If you have a
application for some fancier plotting or surveying, ask for
special consultation. I'm especially interested in scientific
applications.
For those of you who wish to try this method, here are all of my
equations in one place.
HDIST = TAPE * COS (INCL)
RUN (TO) = RUN (FROM) + TAPE
INORTH = HDIST * COS (COMP)
IEAST = HDIST * SIN (COMP)
IUP = TAPE * SIN (INCL)
SNORTH (TO) = SNORTH (FROM) + INORTH
SEAST (TO) = SEAST (FROM) + IEAST
SUP (TO) = SUP (FROM) + IUP
CLOSURE = SQR( [SNORTH {A} - SNORTH {B} ]^ 2 +
[SEAST {A} - SEAST {B} ]^ 2)
CLOSURE percent = CLOSURE * 100 / RUN
SIY9.TXT Calculators and Computers 52
The symbol "^" ["carrot"] means exponentiate or power in
Applesoft and GW- BASIC. The same as "**" on some other
computers and in FORTRAN. The function "^ 2" means to square, to
multiply by itself. Hopefully, by now you know that "*" means
multiply and "/" means divide.
Professional surveyors call north "latitude", and east
"departure". They also call a map a "plat". Gotta keep the
peons convinced that they are stupid.
It is very much easier to blunder with the calculator than with a
hand plot. And a computer can lie with a straight face even
longer than can your favorite politician.
I don't pretend to be able to solve all your problems here. You
are welcome to a copy of any of my programs, but I've always
found it easier to write my own than to make yours work. I have
programs for IBM clone PC/MS-DOS [in GW-BASIC {same as BASICA}],
Apple II [in Applesoft], COCO 2 [cassette BASIC], TRS-80 III
[disk], Commodore [cassette BASIC], and the Texas Instruments
programmable calculator [weird machine code].
Only the Apple II and PC are presently on line and supported, but
they all worked while I was using them. The PC program and the
Apple II program (to a lesser extent) do a lot of things not
covered here. These are calculations which are only practical
with a computer.
I am especially interested in scientific applications.
If you need any custom programming to make my program fit your
computer or your application, I will help. But unless your
computer is sitting on my desk, you will have to do most of the
work.
This compuscript was originally written longhand and then typed
to make a master for xerographic copying. Typing was a
nightmare, and the revisions were a host of tribulations.
Writing on a computer compares with writing on a typewriter, just
like writing with a ballpoint pen compares with writing with a
goose quill and inkberries.
SIY9.TXT Calculators and Computers 53
As a special one time offer, I will sell to some lucky fool one
Radio Shuck COCO 2 computer, complete with my CAVEMAP surveying
program for only $50. Be the first to buy this wonderful piece
of technology. I have been told that cartridges [an EPROM in an
expensive box] are still available for such activities as
Pac-Man [Pac-Person? {Pac-Perchild??}] and Donkey Dong. If it
won't work as a babysitter, it still might work as a doorstop.
Here is a simple BASIC program which should work on any
computer. Try it. It is the program SIY2LINR on my PC disk.
1 D=.01745329:PRINT"Instructions in SIY*.TXT
Survey It Yourself: The Poor Man's Guide to Land Surveying
(c)1990, DP_BYTER -=>Go forth & exponentiate^<=-
½ Fast Software
CAVE Inc
Ritner KY 42639
606/376-3137
Quick. Easy. Inexpensive instruments. No magic.
2 INPUT"Compass ($41)";CO:INPUT"Tape ($27)";TA:SN=SN+TA*COS(CO*D):
SE=SE+TA*SIN(CO*D):PRINT"SNORTH =";SN,"SEAST =";SE:GOTO 2
'Do you believe in magic? Y\N
This is interpreted BASIC. You need GWBASIC or BASICA or help.
3 'Enter direction (as 0 to 360 degrees) and distance from land
description. SNORTH = distance north of beginning station,
SEAST = distance east. Plot on graph paper, connect the dots,
this is the map, or plat, of the property.
This is too easy for a 2-liner.
Actually, I can do it with only one line of code.
1 D=.01745329:INPUT"Compass ";CO:INPUT"Tape ";TA:SN=SN+TA*COS(CO*D):
SE=SE+TA*SIN(CO*D): PRINT"SNORTH =";SN,"SEAST =";SE:GOTO 1
'DP_BYTER, 1/2 Fast Software, Ritner, KY 42639 606/376-3137
Copyright (c)1994 by David Perry Beiter
If you have any questions, problems, or comments, write or call
me. Dave Beiter, CAVE Inc, 1/2 Fast Road, Ritner KY 42639.
606/376-3137.
MCI Mail: 635-1762
byter@mcimail.com
X.400: c=US;a=MCI;s=BEITER;d=id=6351762
from CIS: >MCIMAIL 635-1762 (include your name in the text)