int
main(int argc, char *argv[])
{
/* ============== Begin variable definition section. ============= */
/*
* i, j, and k are counting variables used in loops and such. M is the
* number of lines to be plotted and N is the number of sample points
* for each line.
*/
int i, j, k, M, N, leglen;
/*
* x is a pointer to an array containing the N x-coordinate values. y
* points to an array of M pointers each of which points to an array
* containing the N y-coordinate values for that line.
*/
PLFLT *x, **y;
/* Define storage for the min and max values of the data. */
PLFLT xmin, xmax, ymin, ymax, xdiff, ydiff;
/* Define storage for the filename and define the input file pointer. */
char filename[80], string[80], tmpstr[80];
FILE *datafile;
/* Here are the character strings that appear in the plot legend. */
static char *legend[] =
{
"Aardvarks",
"Gnus",
"Llamas",
NULL}; /* Make sure last element is NULL */
/* ============== Read in data from input file. ============= */
/* Parse and process command line arguments */
(void) plparseopts(&argc, argv, PL_PARSE_FULL);
/* First prompt the user for the input data file name */
printf("Enter input data file name. ");
scanf("%s", filename);
/* and open the file. */
datafile = fopen(filename, "r");
if (datafile == NULL) /* error opening input file */
error("Error opening input file.");
/* Read in values of M and N */
k = fscanf(datafile, "%d %d", &M, &N);
if (k != 2) /* something's wrong */
error("Error while reading data file.");
/* Allocate memory for all the arrays. */
x = (PLFLT *) malloc(N * sizeof(PLFLT));
if (x == NULL)
error("Out of memory!");
y = (PLFLT **) malloc(M * sizeof(PLFLT *));
if (y == NULL)
error("Out of memory!");
for (i = 0; i < M; i++) {
y[i] = (PLFLT *) malloc(N * sizeof(PLFLT));
if (y[i] == NULL)
error("Out of memory!");
}
/* Now read in all the data. */
for (i = 0; i < N; i++) { /* N points */
k = fscanf(datafile, "%f", &x[i]);
if (k != 1)
error("Error while reading data file.");
for (j = 0; j < M; j++) { /* M lines */
k = fscanf(datafile, "%f", &y[j][i]);
if (k != 1)
error("Error while reading data file.");
}
}
/* ============== Graph the data. ============= */
/* Set graph to portrait orientation. (Default is landscape.) */
/* (Portrait is usually desired for inclusion in TeX documents.) */
plsori(1);
/* Initialize plplot */
plinit();
/*
* We must call pladv() to advance to the first (and only) subpage.
* You might want to use plenv() instead of the pladv(), plvpor(),
* plwind() sequence.
*/
pladv(0);
/*
* Set up the viewport. This is the window into which the data is
* plotted. The size of the window can be set with a call to
* plvpor(), which sets the size in terms of normalized subpage
* coordinates. I want to plot the lines on the upper half of the
* page and I want to leave room to the right of the figure for
* labelling the lines. We must also leave room for the title and
* labels with plvpor(). Normally a call to plvsta() can be used
* instead.
*/
plvpor(0.15, 0.70, 0.5, 0.9);
/*
* We now need to define the size of the window in user coordinates.
* To do this, we first need to determine the range of the data
* values.
*/
xmin = xmax = x[0];
ymin = ymax = y[0][0];
for (i = 0; i < N; i++) {
if (x[i] < xmin)
xmin = x[i];
if (x[i] > xmax)
xmax = x[i];
for (j = 0; j < M; j++) {
if (y[j][i] < ymin)
ymin = y[j][i];
if (y[j][i] > ymax)
ymax = y[j][i];
}
}
/*
* Now set the size of the window. Leave a small border around the
* data.
*/
xdiff = (xmax - xmin) / 20.;
ydiff = (ymax - ymin) / 20.;
plwind(xmin - xdiff, xmax + xdiff, ymin - ydiff, ymax + ydiff);
/*
* Call plbox() to draw the axes (see the PLPLOT manual for
* information about the option strings.)
*/
plbox("bcnst", 0.0, 0, "bcnstv", 0.0, 0);
/*
* Label the axes and title the graph. The string "#gm" plots the
* Greek letter mu, all the Greek letters are available, see the
* PLplot manual.
*/
pllab("Time (weeks)", "Height (#gmparsecs)", "Specimen Growth Rate");
/*
* Plot the data. plpoin() draws a symbol at each point. plline()
* connects all the points.
*/
for (i = 0; i < M; i++) {
plpoin(N, x, y[i], i + OFFSET);
plline(N, x, y[i]);
}
/*
* Draw legend to the right of the chart. Things get a little messy
* here. You may want to remove this section if you don't want a
* legend drawn. First find length of longest string.
*/
leglen = 0;
for (i = 0; i < M; i++) {
if (legend[i] == NULL)
break;
j = strlen(legend[i]);
if (j > leglen)
leglen = j;
}
/*
* Now build the string. The string consists of an element from the
* legend string array, padded with spaces, followed by one of the
* symbols used in plpoin above.
*/
for (i = 0; i < M; i++) {
if (legend[i] == NULL)
break;
strcpy(string, legend[i]);
j = strlen(string);
if (j < leglen) { /* pad string with spaces */
for (k = j; k < leglen; k++)
string[k] = ' ';
string[k] = '\0';
}
/* pad an extra space */
strcat(string, " ");
j = strlen(string);
/* insert the ASCII value of the symbol plotted with plpoin() */
string[j] = i + OFFSET;
string[j + 1] = '\0';
/* plot the string */
plmtex("rv", 1., 1. - (double) (i + 1) / (M + 1), 0., string);
}
/* Tell plplot we are done with this page. */
pladv(0); /* advance page */
/* Don't forget to call plend() to finish off! */
plend();
exit(0);
}
int
main( int argc, const char *argv[] )
{
int i;
PLFLT dtr, theta, dx, dy, r, offset;
char text[4];
static PLFLT x0[361], y0[361];
static PLFLT x[361], y[361];
dtr = M_PI / 180.0;
for ( i = 0; i <= 360; i++ )
{
x0[i] = cos( dtr * i );
y0[i] = sin( dtr * i );
}
// Parse and process command line arguments
(void) plparseopts( &argc, argv, PL_PARSE_FULL );
// Set orientation to portrait - note not all device drivers
// support this, in particular most interactive drivers do not
plsori( 1 );
// Initialize plplot
plinit();
// Set up viewport and window, but do not draw box
plenv( -1.3, 1.3, -1.3, 1.3, 1, -2 );
// Draw circles for polar grid
for ( i = 1; i <= 10; i++ )
{
plarc( 0.0, 0.0, 0.1 * i, 0.1 * i, 0.0, 360.0, 0.0, 0 );
}
plcol0( 2 );
for ( i = 0; i <= 11; i++ )
{
theta = 30.0 * i;
dx = cos( dtr * theta );
dy = sin( dtr * theta );
// Draw radial spokes for polar grid
pljoin( 0.0, 0.0, dx, dy );
sprintf( text, "%d", ROUND( theta ) );
// Write labels for angle
if ( theta < 9.99 )
{
offset = 0.45;
}
else if ( theta < 99.9 )
{
offset = 0.30;
}
else
{
offset = 0.15;
}
// Slightly off zero to avoid floating point logic flips at 90 and 270 deg.
if ( dx >= -0.00001 )
plptex( dx, dy, dx, dy, -offset, text );
else
plptex( dx, dy, -dx, -dy, 1. + offset, text );
}
// Draw the graph
for ( i = 0; i <= 360; i++ )
{
r = sin( dtr * ( 5 * i ) );
x[i] = x0[i] * r;
y[i] = y0[i] * r;
}
plcol0( 3 );
plline( 361, x, y );
plcol0( 4 );
plmtex( "t", 2.0, 0.5, 0.5, "#frPLplot Example 3 - r(#gh)=sin 5#gh" );
// Close the plot at end
plend();
exit( 0 );
}
