#10 (02/17/2025)

Sorting algorithm (bubble sort)

x[0] x[1] x[2] x[3] x[4] x[5]
45 67 12 34 25 39
x[0] x[1] x[2] x[3] x[4] x[5]
45 67 12 34 25 39
x[0] x[1] x[2] x[3] x[4] x[5]
45 12 67 34 25 39
x[0] x[1] x[2] x[3] x[4] x[5]
45 12 34 67 25 39
x[0] x[1] x[2] x[3] x[4] x[5]
45 12 34 25 67 39
x[0] x[1] x[2] x[3] x[4] x[5]
45 12 34 25 39 67
The largest element has bubbled to the top index of the array. In general, a bubble step is performed by the loop: 
#define N 6
for (i=0; i < N-1; i++)
if (x[i] > x[i+1]) swap(&x[i], &x[i+1])
If this process is repeated again for (i=0; i< N-2; i++), then, the second largest element is located at the second right most place.
Repeat this for (i=0; i< N-3; i++), for (i=0; i< N-4; i++), for (i=0; i< N-5; i++) 
#include <stdio.h>
#define N 6

void swap(float *a, float *b)
{
float tmp;
tmp=*a;
*a=*b;
*b=tmp;
}

int main()
{

float a[N]={45, 67, 12, 34, 25, 39};
int  i, j;

for (j=1; j < N; j++)
 {for (i=0; i< N-j; i++)
   if ( a[i]> a[i+1]) swap(&a[i], &a[i+1]);
  }

 for (i=0;i<N; i++) printf("%f ", a[i]);
   printf("\n");
 return 0;
}
Demo

Plotting (GNUPlot)

gnuplot.gif
Download the binary GNUPlot (Version 4.4, only 1.2MB) for Windows. If you must have the latest version, download Version 6 (the current version) from here. Once downloaded, extract all the files into a subdirectory and run wgnuplot.exe from there. 


gnuplot > set title "My graph"
gnuplot > plot x**3-x-1
gnuplot > plot sin(x) with dots (w d)
gnuplot > plot sin(x) with impulse (w i)
gnuplot > plot [-5:5] sin(x)/(x**2+1)
gnuplot > plot [-pi:pi] sin(x), sin(2*x), sin(3*x)
gnuplot > set xlabel "My x axis"
gnuplot > set ylabel "My y axis"
gnuplot > plot [-4:4] [0:10] x/exp(x)
gnuplot > splot [-pi:pi] [-2*pi:3*pi] sin(x*y)
gnuplot > plot [-4:4] [0:10] x/exp(x)

gnuplot> set isosamples 100
gnuplot> set hidden3d
gnuplot> set contour base
gnuplot> splot [0:pi][0:pi] sin(x*y)
gnuplot>

gnuplot > quit
An example of generating a data file from C and export the file to gnuplot to draw the graph. 


#include <stdio.h>
#include <math.h>

int main()
{
int i;
float x;
for (i=0; i<10; i++)
 {
   x = 0.1*i;
   printf("%f %f\n", x , sin(x));
 }
   return 0;
}






$ gcc -lm thisprogram.c
$ a.out > junk.dat
$ gnuplot
gnuplot > plot "junk.dat" with lines
gnuplot > plot "junk.dat", 3*x+12

Transferring files between omega.uta.edu and local machine

Download WinSCP (latest here 6.1.2).
  1. New
  2. Hostname omega.uta.edu
  3. Username: NetID
  4. Password: your UTA password
  5. Login
WinSCP.jpg

From CMD line

If you know the name and the location of the file you want to transfer, you can do it directly.
  1. Win+R, cmd
  2. cd to_your_folder
  3. scp abs1234@omega.uta.edu:program.data . (from omega.uta.edu to the local machine)

Saving GNUPlot graphs in GIF format/GIF animation

For a graphic viewer, IrfanView is recommended.

To create a GIF animation, download this tiny file, mergegif.exe (64 bit PC) or mergegif32.exe (32 bit old PC) 1
Issue the following commands in GNUPlot to create three GIF files. 


cd "c:/tmp"
set term gif size 320,240
set output "1.gif"
plot sin(x)

set output "2.gif"
plot sin(2*x)

set output "3.gif"
plot sin(3*x)
quit
After that, open a DOS window and issue 


$ cd \tmp
$ mergegif -l0 1.gif 2.gif 3.gif > animation.gif
$ start animation.gif

Creating GifAnimation from within GNUPlot



cd "c:/tmp"
set term gif animate
set output "animation.gif"
plot sin(x)
plot sin(2*x)
plot sin(3*x)
quit

Footnotes:

1If your OS is x86 (32-bit) or other platforms, try compiling the source code yourself using gcc available here.

File translated from TEX by TTH, version 4.03.
On 18 Feb 2025, 21:04.