Media Share 9/MEDIASHARE_09.ISO/progmisc/asmlib.zip/CURVEFIT.ASM

Assembly Source File | 1992-06-04 | 7KB | 391 lines

; CURVEFIT.ASM - Sample program for ASMLIB
; Programmer: Douglas Herr
; date: 5/24/1992
;
; CURVEFIT displays a series of points on the screen and calculates
; the equations for curves to fit the data.
; CURVEFIT has not been optimized particularly, so it's likely
; that much could be done to make it smaller and/or faster.
; CURVEFIT is intended as an illustration of ASMLIB use.

include    asm.inc

public  curvefit

; non-library external subroutines
extrn    graphmode:proc, textmode:proc

; standard library external subroutines
extrn   ucinit:proc, uc2sys:proc, viewlimit:proc
extrn   drawline:proc, drawbox:proc, fillbox:proc
extrn    gcenter:proc, gprintup:proc, smalltext:proc
extrn    gprint:proc, stdtext:proc, mathchip:proc
extrn    getkey:proc, gcolor:proc, fillpattern:proc
extrn    maxi2:proc, mini2:proc, strlen:proc
extrn    linefiti2:proc, quadfiti2:proc, cubefiti2:proc
extrn    psolvef4:proc


.data
; bar graph data for y-axis
; any integers from -32768 to 32767 may be used
bardata    dw 0,50,150,140,160,100,50,60,150,210,420,450,520
npoints    equ ($-bardata) shr 1

extrn    x0:word        ; xmin
extrn    y0:word        ; ymin
extrn    x1:word        ; xmax
extrn    y1:word        ; ymax

a    dd 0
b    dd 0
c    dd 0
d    dd 0

fit_data    label word
    dw (npoints shl 1) dup ('■■')

color    dw 1
star    db '*',0


; titles

extrn    teenager:byte
extrn    subtitle:byte
extrn    xaxis:byte
extrn    cost:byte

no_mathchip    db 'Math coprocessor required',0Dh,0Ah,7,'$'
linefit        db ' linear fit',0
quadfit        db ' quadratic fit',0
cubefit        db ' cubic fit',0
measured    db ' measured data',0

.code
curvefit    proc
    cld
    call    mathchip
    or    ax,ax
    jnz    c0
    lea    dx,no_mathchip
    jmp    short c1
c0:    call    graphmode
    jnc    b0        ; continue if no error
c1:    mov    ah,9        ; else use DOS to write error message
    int    21h
    jmp    exit        ; & exit

b0:    push    ds
    pop    es
    lea    di,bardata
    mov    cx,npoints
    call    maxi2
    shl    ax,1
    mov    bx,di
    add    bx,ax
    mov    ax,[bx]        ; get maximum value
    mov    y1,ax

    call    mini2
    shl    ax,1
    mov    bx,di
    add    bx,ax
    mov    ax,[bx]        ; get minimum value
    or    ax,ax        ; use 0 if min > 0
    js    b1
    xor    ax,ax
b1:    mov    y0,ax

    mov    x0,0
    mov    x1,npoints

    push    x0
    push    y0
    push    x1
    push    y1

; establish coordinates, leaving room at edges for titles
    mov    cl,3
    call    set_coordinates

    lea    bx,x0
        call    ucinit

; plot the data
    mov    ax,15
    call    gcolor
    mov    x0,0
    mov    x1,1
    mov    y1,0
    lea    si,bardata
    mov    cx,npoints    ; number of data points
    call    smalltext
point:    push    cx
    lodsw
    push    si
    mov    y0,ax
    lea    bx,x0
    call    uc2sys
    mov    ax,4[bx]
    sub    ax,[bx]
    shr    ax,1
    sub    ax,4        ; center the marker on the point
    add    [bx],ax
    sub    word ptr 2[bx],4

    mov    dx,bx        ; DS:[DX] points to position data
    lea    si,star
    call    gprint
    inc    x0
    inc    x1
    pop    si
    pop    cx
    loop    point

    pop    y1
    pop    x1
    pop    y0
    pop    x0

; draw the graph axes
    mov    ax,15
    call    gcolor
    push    y0
    push    y1
    mov    ax,0
    mov    y0,ax
    mov    y1,ax
    lea    bx,x0
    call    uc2sys
    call    drawline
    pop    y1
    pop    y0
    mov    ax,x0
    mov    x1,ax
    lea    bx,x0
    call    uc2sys
    call    drawline

; a simple descriptive legend
    mov    ax,9        ; linear fit color
    call    gcolor
    mov    ax,2[bx]    ; y0
    cmp    ax,6[bx]
    jb    c5
    mov    ax,6[bx]
c5:    add    ax,4
    mov    2[bx],ax
    mov    6[bx],ax
    mov    ax,[bx]
    cmp    ax,4[bx]
    jb    c6
    mov    ax,4[bx]
c6:    add    ax,10
    mov    [bx],ax        ; line length
    add    ax,30
    mov    4[bx],ax
    call    drawline

    lea    si,linefit
    call    print_label

; quadratic label
    mov    ax,12
    call    gcolor
    mov    ax,2[bx]
    add    ax,12
    mov    2[bx],ax
    mov    6[bx],ax
    call    drawline

    mov    ax,4[bx]
    lea    si,quadfit
    call    print_label

; cubic label
    mov    ax,14
    call    gcolor
    mov    ax,2[bx]
    add    ax,12
    mov    2[bx],ax
    mov    6[bx],ax
    call    drawline

    mov    ax,4[bx]
    lea    si,cubefit
    call    print_label

; label for measured data
    mov    ax,2[bx]
    add    ax,12
    mov    2[bx],ax
    add    word ptr [bx],4
    sub    word ptr 2[bx],4
    mov    dx,bx
    lea    si,star
    call    gprint

    add    word ptr 2[bx],4
    mov    ax,4[bx]
    lea    si,measured
    call    print_label

; print main title
    mov    ax,15        ; bright white
    call    gcolor
    call    stdtext        ; larger text if not CGA
    mov    y0,0
    lea    dx,x0
    lea    si,teenager
    call    gcenter

; print subtitle
    call    smalltext    ; 8x8 character size
    lea    si,subtitle
    mov    y0,16
    call    gcenter

; print x-axis label
    call    viewlimit
    mov    ax,2[bx]    ; maximum y
    push    ax
    sub    ax,10
    mov    y0,ax
    lea    si,xaxis
    call    gcenter

; print y-axis label
    lea    bx,cost
    call    strlen
    mov    si,bx
    mov    bx,cx
    mov    cl,3
    shl    bx,cl        ; length of string in pixels
    pop    ax        ; maximum y
    add    ax,bx        ; maximum y plus len(string)
    shr    ax,1
    mov    y0,ax
    mov    x0,0
    call    gprintup

; convert data to linefit format
    lea    di,fit_data
    mov    bx,di        ; save for LineFit
    push    ds
    pop    es
    mov    ax,1
    mov    cx,npoints
    lea    si,bardata
c9:    stosw
    movsw
    inc    ax
    loop    c9

; calculate line equation
    mov    cx,npoints
    call    linefiti2

    fstp    a
    fstp    b

; solve for y given x
    mov    ax,9
    call    gcolor        ; bright blue
    mov    dx,1        ; 1st order equation
    call    solve0

; calculate quadratic equation
    lea    bx,fit_data
    mov    cx,npoints
    call    quadfiti2
    fstp    a
    fstp    b
    fstp    c

; solve for y given x
    mov    ax,12        ; bright red
    call    gcolor
    mov    dx,2        ; 2nd order equation
    call    solve0

; calculate cubic equation
    lea    bx,fit_data
    mov    cx,npoints
    call    cubefiti2
    fstp    a        ; save equation coefficients
    fstp    b
    fstp    c
    fstp    d

; solve for y given x
    mov    ax,14        ; yellow
    call    gcolor
    mov    dx,3        ; 3rd order equation
    call    solve0

; wait for any keypress, then return to text mode
    call    getkey
    call    textmode
exit:    ret

curvefit    endp

; SET_COORDINATES is outside MYMAIN because it'a always a near call
; this subroutine adjusts the user-defined coordinates to allow
; room on all sides for titles, etc.
set_coordinates:
    lea    si,x0        ; adjust x-coordinates
    call    s0
    add    si,2        ; now do it for y
s0:    mov    ax,4[si]
    sub    ax,[si]        ; delta x
    shr    ax,cl
    sub    [si],ax
    add    4[si],ax
    ret

; SOLVE0 is outside MYMAIN because it's always a near call
solve0:    lea    si,a
    mov    cx,npoints+1
    mov    x0,0
    mov    y0,0
    mov    x1,0
solve1:    push    cx
    mov    cx,dx
    finit
    fild    x1
    call    psolvef4
    fistp    y1
    cmp    x1,0
    je    solve2
    lea    bx,x0
    call    uc2sys
    call    drawline
solve2:    push    x1
    push    y1
    pop    y0
    pop    x0
    inc    x1
    pop    cx
    loop    solve1
    ret

print_label:
    push    [bx]
    push    2[bx]

    add    ax,3
    mov    [bx],ax
    mov    ax,15
    call    gcolor
    sub    word ptr 2[bx],3
    mov    dx,bx
    call    gprint

    pop    2[bx]
    pop    [bx]
    ret

    end