Sometime the scaling routine in xforms does misbehave. I'll
look at your routine. Next release will have the capbility
of arbitary non-uniform and user-specified scaling as in
"tic1@0.1 tic2@0.5 tic3@0.6".
---moini@eleceng.adelaide.edu.au wrote:
>
> # To subscribers of the xforms list from
moini@eleceng.adelaide.edu.au :
>
> The current ticking functions for xyplot seem to generate strange
numbers
> very often.
> Here are a couple of functions that I use to generate more sensible
tick
> numbers for my xyplot print outs.
>
> People can give these a try and if everyone becomes happy, these may
be
> implemented for the xyplot.
>
> Note that after these functions the program should check the numbers
> against min and max.
> In my program I also check whether the size of the fonts and amount of
> available space allows a reasonable spacing between the numbers.
>
>
/**************************************************************************/
>
/**************************************************************************/
> #include <math.h>
> #include <stdio.h>
> #include <stdlib.h>
> #define DEBUG_PRINT
> int DEBUG=0;
>
> /**************************************************/
> double dabs(double x)
> {
> if(x>0.0)return x;
> else return (-x);
> }
>
> /**************************************************/
> double
> round(double x)
> {
> return (double)((int)(x < 0 ? x - 0.5 : x + 0.5));
> }
> /**************************************************/
> int logscale(double xmin,double xmax,int n ,double *xout, int *nout,
int *loglin)
> {
>
> double xo1,xo2,ticsep,xo[100];
> int i=0,nmin,nmax,nticsout;
>
> /*
> * Check whether proper input values were supplied.
> */
> if (xmin >= xmax || n <= 0 || xmin <= 0.0) {
> fprintf(stderr, "logscale: Improper values supplied as input\n");
> if (xmin <= 0.0)
> fprintf(stderr, "Zero or negative minimum value input: %f\n",
xmin);
>
> return(1);
> }
> #ifdef DEBUG_PRINT
> if(DEBUG)printf("log1\n");
> #endif
>
>
> /*
> * Values are translated from the linear region to the logarithmic
> */
>
> #ifdef DEBUG_PRINT
> if(DEBUG)printf("ll1 %d\n",(int)(log10(xmax)-log10(xmin)));
> #endif
> if((((int)(log10(xmax)-log10(xmin)))>=1.0) && (xmax/xmin>3.0)){
>
>
> nmin=(int)(floor(log10(xmin)));
> nmax=(int)(ceil(log10(xmax)));
> *nout=nmax-nmin+1;
>
>
> for(i=0;i<=(nmax-nmin);i++){
> xout[i]=pow(10.0,(double)(i+nmin));
> #ifdef DEBUG_PRINT
> if(DEBUG)printf("log2 %d %g\n",i,xout[i]);
> #endif
> }
> *loglin=1;
> }
> else{
> #ifdef DEBUG_PRINT
> if(DEBUG)printf("log3\n");
> #endif
> *loglin=0;
> *nout=n;
> linscale(xmin,xmax,*nout, xo, &nticsout);
> xo1=xo[0];
> xo2=xo[nticsout];
> ticsep=xo[1]-xo[0];
> *nout=nticsout;
>
>
>
> for(i=0;i<= *nout;i++){
> xout[i]=xo1+ticsep*(double)i;
> #ifdef DEBUG_PRINT
> if(DEBUG)printf("log3 %d %g\n",i,xout[i]);
> #endif
> }
> #ifdef DEBUG_PRINT
> if(DEBUG)printf("log1\n");
> #endif
>
>
> }
>
> #ifdef DEBUG_PRINT
> if(DEBUG){
> for(i=0;i<*nout;i++){
> printf("%g ",xout[i]);
> }
> printf("nout=%d\n",*nout);
> }
> #endif
>
>
> return 0;
>
>
> }
>
>
>
> /**************************************************/
> double ten2pow(int i)
> {
> double a = 1.0;
> int j;
>
> #ifdef DEBUG_PRINT
> if(DEBUG)printf("ten2p %d\n",i);
> #endif
> if (i > 0)
> for (j = 0; j < i; j++)
> a *= 10.0;
> else if (i < 0)
> for (j = 0; j > i; j--)
> a /= 10.0;
>
> #ifdef DEBUG_PRINT
> if(DEBUG)printf("ten2p\n");
> #endif
> return (a);
> }
>
>
> /**************************************************/
> int
> linscale(double min,double max,int n,double *xout,int *nout)
> {
> static double vint[] = { 1.0, 2.0, 5.0, 10.0 };
> static double sqr[] = { 1.414214, 3.162278, 7.071068 };
> double fn, a, al, b, fm1;
> double dist,minp,maxp;
> static double del = 0.000002;
> char tmp_s[256];
> int i,nal,m1,m2;
> int changed_minp=0;
>
> #ifdef DEBUG_PRINT
> if(DEBUG)printf("lin1 %g %g %d\n",min,max,n);
> #endif
>
> /*
> * check whether proper input values were supplied
> */
>
> if (min > max || n < 0) {
> fprintf(stderr,"Improper input supplied %f %f %d\n", min, max,
n);
> return(1);
> }
>
> #ifdef DEBUG_PRINT
> if(DEBUG)printf("lin1\n");
> #endif
> fn = (double) n;
>
> /*
> * find approximate interval size a
> */
>
> a = (max - min) / fn;
> if (max==min) {
> for(i=0;i<n;i++){
> xout[i]=min;
> }
> *nout=n;
> return (0);
> }
>
> al = log10((double)a);
> nal = (int) al;
> if (a < 1.0)
> nal -= 1;
>
> /*
> * a is scaled into variable named b between 1 and 10
>
=== message truncated ===
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