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gnuplot.cpp
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gnuplot.cpp
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/**
* This is the source code for a set of wrapper functions to make calls
* to gnuplot. Gnuplot is a freely available, command-driven graphical
* display tool for Unix. It compiles and works quite well on a number
* of Unix flavours as well as other operating systems. The following
* module enables sending display requests to gnuplot through simple
* C/C++ calls.
*
* The module was adapted from the source code provided freely online
* by N. Devillard, Revision 2.10, September 1998.
*/
#include "gnuplot.h"
/* Maximal size of a gnuplot command */
#define GP_CMD_SIZE 2048
/* Maximal size of a plot title */
#define GP_TITLE_SIZE 80
/* Maximal size for an equation */
#define GP_EQ_SIZE 512
/* Maximal size of a name in the PATH */
#define PATH_MAXNAMESZ 4096
/* Define P_tmpdir if not defined (this is normally a POSIX symbol) */
#ifndef P_tmpdir
#define P_tmpdir "."
#endif
/**
*@brief Find out where a command lives in your PATH.
*@param pname Name of the program to look for.
*@return pointer to statically allocated character string.
*
* This is the C equivalent to the 'which' command in Unix. It parses
* out your PATH environment variable to find out where a command
* lives. The returned character string is statically allocated within
* this function, i.e. there is no need to free it. Beware that the
* contents of this string will change from one call to the next,
* though (as all static variables in a function).
* The input character string must be the name of a command without
* prefixing path of any kind, i.e. only the command name. The returned
* string is the path in which a command matching the same name was
* found.
* Examples (assuming there is a prog named 'hello' in the cwd):
*@verbatim
*gnuplot_get_program_path("hello") returns "."
*gnuplot_get_program_path("ls") returns "/bin"
*gnuplot_get_program_path("csh") returns "/usr/bin"
*gnuplot_get_program_path("/bin/ls") returns NULL
*@endverbatim
*/
char* gnuplot_get_program_path(char* pname) {
int i, j, lg;
char* path;
static char buf[PATH_MAXNAMESZ];
/* Trivial case: try in CWD */
sprintf(buf, "./%s", pname);
if (access(buf, X_OK)==0) {
sprintf(buf, ".");
return buf;
}
/* Try out in all paths given in the PATH variable */
buf[0] = 0;
path = getenv("PATH");
if (path!=NULL) {
for (i=0; path[i]; ) {
for (j=i; (path[j]) && (path[j]!=':'); j++);
lg = j - i;
strncpy(buf, path + i, lg);
if (lg == 0) buf[lg++] = '.';
buf[lg++] = '/';
strcpy(buf + lg, pname);
if (access(buf, X_OK) == 0) {
/* Found it! */
break;
}
buf[0] = 0;
i = j;
if (path[i] == ':') i++;
}
}
else
fprintf(stderr, "PATH variable not set\n");
/* If the buffer is still empty, the command was not found */
if (buf[0] == 0) return NULL;
/* Otherwise truncate the command name to yield path only */
lg = strlen(buf) - 1;
while (buf[lg]!='/') {
buf[lg]=0;
lg --;
}
buf[lg] = 0;
return buf;
}
/**
*@brief Opens up a gnuplot session, ready to receive commands.
*@return Newly allocated gnuplot control structure.
*
* This opens up a new gnuplot session, ready for input. The struct
* controlling a gnuplot session should remain opaque and only be
* accessed through the provided functions.
* The session must be closed using gnuplot_close().
*/
gnuplot_ctrl* gnuplot_init(void) {
gnuplot_ctrl* handle;
if (getenv("DISPLAY") == NULL)
fprintf(stderr, "cannot find DISPLAY variable: is it set?\n");
if (gnuplot_get_program_path((char*)"gnuplot")==NULL) {
fprintf(stderr, "cannot find gnuplot in your PATH");
return NULL;
}
/* Structure initialization */
handle = (gnuplot_ctrl*)malloc(sizeof(gnuplot_ctrl));
handle->nplots = 0;
gnuplot_setstyle(handle, (char*)"points");
handle->ntmp = 0;
handle->gnucmd = popen("gnuplot", "w");
if (handle->gnucmd == NULL) {
fprintf(stderr, "error starting gnuplot\n");
free(handle);
return NULL;
}
return handle;
}
/**
*@brief Closes a gnuplot session previously opened by gnuplot_init()
*@param handle Gnuplot session control handle.
*@return void
*
* Kills the child PID and deletes all opened temporary files.
* It is mandatory to call this function to close the handle, otherwise
* temporary files are not cleaned and child process might survive.
*/
void gnuplot_close(gnuplot_ctrl* handle) {
int i;
if (pclose(handle->gnucmd) == -1) {
fprintf(stderr, "problem closing communication to gnuplot\n");
return;
}
if (handle->ntmp) {
for (i=0; i<handle->ntmp; i++)
remove(handle->to_delete[i]);
}
free(handle);
return;
}
/**
* @brief Sends a command to an active gnuplot session.
* @param handle Gnuplot session control handle
* @param cmd Command to send, same as a printf statement.
*
* This sends a string to an active gnuplot session, to be executed.
* There is strictly no way to know if the command has been
* successfully executed or not.
* The command syntax is the same as printf.
*
* Examples:
*
* @code
* gnuplot_cmd(g, "plot %d*x", 23.0);
* gnuplot_cmd(g, "plot %g * cos(%g * x)", 32.0, -3.0);
* @endcode
*
* Since the communication to the gnuplot process is run through
* a standard Unix pipe, it is only unidirectional. This means that
* it is not possible for this interface to query an error status
* back from gnuplot.
*/
void gnuplot_cmd(gnuplot_ctrl* handle, char* cmd, ...) {
va_list ap;
char local_cmd[GP_CMD_SIZE];
va_start(ap, cmd);
vsprintf(local_cmd, cmd, ap);
va_end(ap);
strcat(local_cmd, "\n");
fputs(local_cmd, handle->gnucmd);
fflush(handle->gnucmd);
return;
}
/**
* @brief Change the plotting style of a gnuplot session.
* @param h Gnuplot session control handle
* @param plot_style Plotting-style to use (character string)
* @return void
*
* The provided plotting style is a character string. It must be one of
* the following:
*
* - lines
* - points
* - linespoints
* - impulses
* - dots
* - steps
* - errorbars
* - boxes
* - boxeserrorbars
*/
void gnuplot_setstyle(gnuplot_ctrl* h, char* plot_style) {
if (strcmp(plot_style, "lines") &&
strcmp(plot_style, "points") &&
strcmp(plot_style, "linespoints") &&
strcmp(plot_style, "impulses") &&
strcmp(plot_style, "dots") &&
strcmp(plot_style, "steps") &&
strcmp(plot_style, "errorbars") &&
strcmp(plot_style, "boxes") &&
strcmp(plot_style, "boxerrorbars")) {
fprintf(stderr, "warning: unknown requested style: using points\n");
strcpy(h->pstyle, "points");
}
else
strcpy(h->pstyle, plot_style);
return;
}
/**
* @brief Sets the x label of a gnuplot session.
* @param h Gnuplot session control handle.
* @param label Character string to use for X label.
* @return void
*
* Sets the x label for a gnuplot session.
*/
void gnuplot_set_xlabel(gnuplot_ctrl* h, char* label) {
char cmd[GP_CMD_SIZE];
sprintf(cmd, "set xlabel \"%s\"", label);
gnuplot_cmd(h, cmd);
return;
}
/**
* @brief Sets the y label of a gnuplot session.
* @param h Gnuplot session control handle
* @param label Character string to use for Y label.
* @return void
*
* Sets the y label for a gnuplot session.
*/
void gnuplot_set_ylabel(gnuplot_ctrl* h, char* label)
{
char cmd[GP_CMD_SIZE];
sprintf(cmd, "set ylabel \"%s\"", label);
gnuplot_cmd(h, cmd);
return;
}
/**
* @brief Sets the minimum and maximum y values for a gnuplot session
* @param h Gnuplot session control handle
* @param lower the minimum y value
* @param upper the maximum y value
*/
void gnuplot_set_yrange(gnuplot_ctrl* h, int lower, int upper) {
std::stringstream cmd;
cmd << "set yrange [" << lower << ":" << upper << "]";
gnuplot_cmd(h, (char*)cmd.str().c_str());
}
/**
* @brief Sets the minimum and maximum y values for a gnuplot session
* @param h Gnuplot session control handle
* @param lower the minimum y value
* @param upper the maximum y value
*/
void gnuplot_set_yrange(gnuplot_ctrl* h, float lower, float upper) {
std::stringstream cmd;
cmd << "set yrange [" << lower << ":" << upper << "]";
gnuplot_cmd(h, (char*)cmd.str().c_str());
}
/**
* @brief Sets the minimum and maximum y values for a gnuplot session
* @param h Gnuplot session control handle
* @param lower the minimum y value
* @param upper the maximum y value
*/
void gnuplot_set_yrange(gnuplot_ctrl* h, double lower, double upper) {
std::stringstream cmd;
cmd << "set yrange [" << lower << ":" << upper << "]";
gnuplot_cmd(h, (char*)cmd.str().c_str());
}
/**
* @brief Sets the minimum and maximum x values for a gnuplot session
* @param h Gnuplot session control handle
* @param lower the minimum y value
* @param upper the maximum y value
*/
void gnuplot_set_xrange(gnuplot_ctrl* h, int lower, int upper) {
std::stringstream cmd;
cmd << "set xrange [" << lower << ":" << upper << "]";
gnuplot_cmd(h, (char*)cmd.str().c_str());
}
/**
* @brief Sets the minimum and maximum x values for a gnuplot session
* @param h Gnuplot session control handle
* @param lower the minimum y value
* @param upper the maximum y value
*/
void gnuplot_set_xrange(gnuplot_ctrl* h, float lower, float upper) {
std::stringstream cmd;
cmd << "set xrange [" << lower << ":" << upper << "]";
gnuplot_cmd(h, (char*)cmd.str().c_str());
}
/**
* @brief Sets the minimum and maximum x values for a gnuplot session
* @param h Gnuplot session control handle
* @param lower the minimum y value
* @param upper the maximum y value
*/
void gnuplot_set_xrange(gnuplot_ctrl* h, double lower, double upper) {
std::stringstream cmd;
cmd << "set xrange [" << lower << ":" << upper << "]";
gnuplot_cmd(h, (char*)cmd.str().c_str());
}
/**
* @brief Resets a gnuplot session (next plot will erase previous ones).
* @param h Gnuplot session control handle.
* @return void
*
* Resets a gnuplot session, i.e. the next plot will erase all previous
* ones.
*/
void gnuplot_resetplot(gnuplot_ctrl* h) {
int i;
if (h->ntmp) {
for (i=0; i<h->ntmp; i++)
remove(h->to_delete[i]);
}
h->ntmp = 0;
h->nplots = 0;
return;
}
/**
* @brief Saves the current Gnuplot session as a pdf
* @param h Gnuplot session control handle
* @param filename the name of the file the plot will be saved as
*/
void gnuplot_saveplot(gnuplot_ctrl* h, char* filename) {
std::stringstream cmd;
cmd << "set output \"" << filename << ".pdf\"";
gnuplot_cmd(h, (char*)"set term pdf");
gnuplot_cmd(h, (char*)cmd.str().c_str());
}
/**
* @brief Plots a 2d graph from a list of ints
* @param handle Gnuplot session control handle.
* @param d Array of ints.
* @param n Number of values in the passed array.
* @param title Title of the plot.
* @return void
*
* Plots out a 2d graph from a list of ints. The x-coordinate is the
* index of the float in the list, the y coordinate is the int in
* the list.
*
* Example:
*
* @code
* gnuplot_ctrl *h;
* int d[50];
* int i;
*
* h = gnuplot_init();
* for (i=0; i<50; i++) {
* d[i] = (int)(i*i);
* }
* gnuplot_plot_x(h, d, 50, "parabola");
* sleep(2);
* gnuplot_close(h);
* @endcode
*/
void gnuplot_plot_x(gnuplot_ctrl* handle, int* d, int n, char* title) {
int i;
int tmpfd;
char name[128];
char cmd[GP_CMD_SIZE];
char line[GP_CMD_SIZE];
if (handle==NULL || d==NULL || (n<1)) return;
/* Open one more temporary file? */
if (handle->ntmp == GP_MAX_TMP_FILES - 1) {
fprintf(stderr,
"maximum # of temporary files reached (%d): cannot open more",
GP_MAX_TMP_FILES);
return;
}
/* Open temporary file for output */
sprintf(name, "%s/gnuplot-i-XXXXXX", P_tmpdir);
if ((tmpfd=mkstemp(name))==-1) {
fprintf(stderr,"cannot create temporary file: exiting plot");
return;
}
/* Store file name in array for future deletion */
strcpy(handle->to_delete[handle->ntmp], name);
handle->ntmp ++;
/* Write data to this file */
for (i=0; i<n; i++) {
sprintf(line, "%d\n", d[i]);
int writeRet = write(tmpfd, line, strlen(line));
if (writeRet == -1)
printf("Error writing data to a file in gnuplot_x");
}
close(tmpfd);
/* Command to be sent to gnuplot */
if (handle->nplots > 0)
strcpy(cmd, "replot");
else
strcpy(cmd, "plot");
if (title == NULL)
sprintf(line, "%s \"%s\" with %s", cmd, name, handle->pstyle);
else
sprintf(line, "%s \"%s\" title \"%s\" with %s", cmd, name,
title, handle->pstyle);
/* send command to gnuplot */
gnuplot_cmd(handle, line);
handle->nplots++;
return;
}
/**
* @brief Plots a 2d graph from a list of floats
* @param handle Gnuplot session control handle.
* @param d Array of floats.
* @param n Number of values in the passed array.
* @param title Title of the plot.
* @return void
*
* Plots out a 2d graph from a list of floats. The x-coordinate is the
* index of the float in the list, the y coordinate is the float in
* the list.
*
* Example:
*
* @code
* gnuplot_ctrl *h;
* float d[50];
* int i;
*
* h = gnuplot_init();
* for (i=0; i<50; i++) {
* d[i] = (float)(i*i);
* }
* gnuplot_plot_x(h, d, 50, "parabola");
* sleep(2);
* gnuplot_close(h);
* @endcode
*/
void gnuplot_plot_x(gnuplot_ctrl* handle, float* d, int n, char* title) {
int i;
int tmpfd;
char name[128];
char cmd[GP_CMD_SIZE];
char line[GP_CMD_SIZE];
if (handle==NULL || d==NULL || (n<1)) return;
/* Open one more temporary file? */
if (handle->ntmp == GP_MAX_TMP_FILES - 1) {
fprintf(stderr,
"maximum # of temporary files reached (%d): cannot open more",
GP_MAX_TMP_FILES);
return;
}
/* Open temporary file for output */
sprintf(name, "%s/gnuplot-i-XXXXXX", P_tmpdir);
if ((tmpfd=mkstemp(name))==-1) {
fprintf(stderr,"cannot create temporary file: exiting plot");
return;
}
/* Store file name in array for future deletion */
strcpy(handle->to_delete[handle->ntmp], name);
handle->ntmp ++;
/* Write data to this file */
for (i=0; i<n; i++) {
sprintf(line, "%g\n", d[i]);
int writeRet = write(tmpfd, line, strlen(line));
if (writeRet == -1)
printf("Error writing data to a file in gnuplot_x");
}
close(tmpfd);
/* Command to be sent to gnuplot */
if (handle->nplots > 0)
strcpy(cmd, "replot");
else
strcpy(cmd, "plot");
if (title == NULL)
sprintf(line, "%s \"%s\" with %s", cmd, name, handle->pstyle);
else
sprintf(line, "%s \"%s\" title \"%s\" with %s", cmd, name,
title, handle->pstyle);
/* send command to gnuplot */
gnuplot_cmd(handle, line);
handle->nplots++;
return;
}
/**
* @brief Plots a 2d graph from a list of doubles
* @param handle Gnuplot session control handle.
* @param d Array of doubles.
* @param n Number of values in the passed array.
* @param title Title of the plot.
* @return void
*
* Plots out a 2d graph from a list of double. The x-coordinate is the
* index of the double in the list, the y coordinate is the double in
* the list.
*
* Example:
*
* @code
* gnuplot_ctrl *h;
* double d[50];
* int i;
*
* h = gnuplot_init();
* for (i=0; i<50; i++) {
* d[i] = (double)(i*i);
* }
* gnuplot_plot_x(h, d, 50, "parabola");
* sleep(2);
* gnuplot_close(h);
* @endcode
*/
void gnuplot_plot_x(gnuplot_ctrl* handle, double* d, int n, char* title) {
int i;
int tmpfd;
char name[128];
char cmd[GP_CMD_SIZE];
char line[GP_CMD_SIZE];
if (handle==NULL || d==NULL || (n<1)) return;
/* Open one more temporary file? */
if (handle->ntmp == GP_MAX_TMP_FILES - 1) {
fprintf(stderr,
"maximum # of temporary files reached (%d): cannot open more",
GP_MAX_TMP_FILES);
return;
}
/* Open temporary file for output */
sprintf(name, "%s/gnuplot-i-XXXXXX", P_tmpdir);
if ((tmpfd=mkstemp(name))==-1) {
fprintf(stderr,"cannot create temporary file: exiting plot");
return;
}
/* Store file name in array for future deletion */
strcpy(handle->to_delete[handle->ntmp], name);
handle->ntmp ++;
/* Write data to this file */
for (i=0; i<n; i++) {
sprintf(line, "%f\n", d[i]);
int writeRet = write(tmpfd, line, strlen(line));
if (writeRet == -1)
printf("Error writing data to a file in gnuplot_x");
}
close(tmpfd);
/* Command to be sent to gnuplot */
if (handle->nplots > 0)
strcpy(cmd, "replot");
else
strcpy(cmd, "plot");
if (title == NULL)
sprintf(line, "%s \"%s\" with %s", cmd, name, handle->pstyle);
else
sprintf(line, "%s \"%s\" title \"%s\" with %s", cmd, name,
title, handle->pstyle);
/* send command to gnuplot */
gnuplot_cmd(handle, line);
handle->nplots++;
return;
}
/**
* @brief Plot a 2d graph from a list of points.
* @param handle Gnuplot session control handle.
* @param x Pointer to a list of x coordinates.
* @param y Pointer to a list of y coordinates.
* @param n Number of doubles in x (assumed the same as in y).
* @param title Title of the plot.
* @return void
*
* Plots out a 2d graph from a list of points. Provide points through a list
* of x and a list of y coordinates. Both provided arrays are assumed to
* contain the same number of values.
*
* @code
* gnuplot_ctrl *h;
* int x[50];
* int y[50];
* int i;
*
* h = gnuplot_init();
* for (i=0; i<50; i++) {
* x[i] = (int)(i)/10.0;
* y[i] = x[i] * x[i];
* }
* gnuplot_plot_xy(h, x, y, 50, "parabola");
* sleep(2);
* gnuplot_close(h);
* @endcode
*/
void gnuplot_plot_xy(gnuplot_ctrl* handle, int* x, int* y,
int n, char* title) {
int i;
int tmpfd;
char name[128];
char cmd[GP_CMD_SIZE];
char line[GP_CMD_SIZE];
if (handle==NULL || x==NULL || y==NULL || (n<1)) return;
/* Open one more temporary file? */
if (handle->ntmp == GP_MAX_TMP_FILES - 1) {
fprintf(stderr,
"maximum # of temporary files reached (%d): cannot open more",
GP_MAX_TMP_FILES);
return;
}
/* Open temporary file for output */
sprintf(name, "%s/gnuplot-i-XXXXXX", P_tmpdir);
if ((tmpfd=mkstemp(name))==-1) {
fprintf(stderr,"cannot create temporary file: exiting plot");
return;
}
/* Store file name in array for future deletion */
strcpy(handle->to_delete[handle->ntmp], name);
handle->ntmp ++;
/* Write data to this file */
for (i=0; i<n; i++) {
sprintf(line, "%d %d\n", x[i], y[i]);
int writeRet = write(tmpfd, line, strlen(line));
if (writeRet == -1)
printf("Error writing data to a file in gnuplot_xy");
}
close(tmpfd);
/* Command to be sent to gnuplot */
if (handle->nplots > 0)
strcpy(cmd, "replot");
else
strcpy(cmd, "plot");
if (title == NULL)
sprintf(line, "%s \"%s\" with %s", cmd, name, handle->pstyle);
else
sprintf(line, "%s \"%s\" title \"%s\" with %s", cmd, name,
title, handle->pstyle);
/* send command to gnuplot */
gnuplot_cmd(handle, line);
handle->nplots++;
return;
}
/**
* @brief Plot a 2d graph from a list of points.
* @param handle Gnuplot session control handle.
* @param x Pointer to a list of x coordinates.
* @param y Pointer to a list of y coordinates.
* @param n Number of doubles in x (assumed the same as in y).
* @param title Title of the plot.
* @return void
*
* Plots out a 2d graph from a list of points. Provide points through a list
* of x and a list of y coordinates. Both provided arrays are assumed to
* contain the same number of values.
*
* @code
* gnuplot_ctrl *h;
* float x[50];
* float y[50];
* int i;
*
* h = gnuplot_init();
* for (i=0; i<50; i++) {
* x[i] = (float)(i)/10.0;
* y[i] = x[i] * x[i];
* }
* gnuplot_plot_xy(h, x, y, 50, "parabola");
* sleep(2);
* gnuplot_close(h);
* @endcode
*/
void gnuplot_plot_xy(gnuplot_ctrl* handle, float* x, float* y,
int n, char* title) {
int i;
int tmpfd;
char name[128];
char cmd[GP_CMD_SIZE];
char line[GP_CMD_SIZE];
if (handle==NULL || x==NULL || y==NULL || (n<1)) return;
/* Open one more temporary file? */
if (handle->ntmp == GP_MAX_TMP_FILES - 1) {
fprintf(stderr,
"maximum # of temporary files reached (%d): cannot open more",
GP_MAX_TMP_FILES);
return;
}
/* Open temporary file for output */
sprintf(name, "%s/gnuplot-i-XXXXXX", P_tmpdir);
if ((tmpfd=mkstemp(name))==-1) {
fprintf(stderr,"cannot create temporary file: exiting plot");
return;
}
/* Store file name in array for future deletion */
strcpy(handle->to_delete[handle->ntmp], name);
handle->ntmp ++;
/* Write data to this file */
for (i=0; i<n; i++) {
sprintf(line, "%g %g\n", x[i], y[i]);
int writeRet = write(tmpfd, line, strlen(line));
if (writeRet == -1)
printf("Error writing data to a file in gnuplot_xy");
}
close(tmpfd);
/* Command to be sent to gnuplot */
if (handle->nplots > 0)
strcpy(cmd, "replot");
else
strcpy(cmd, "plot");
if (title == NULL)
sprintf(line, "%s \"%s\" with %s", cmd, name, handle->pstyle);
else
sprintf(line, "%s \"%s\" title \"%s\" with %s", cmd, name,
title, handle->pstyle);
/* send command to gnuplot */
gnuplot_cmd(handle, line);
handle->nplots++;
return;
}
/**
* @brief Plot a 2d graph from a list of points.
* @param handle Gnuplot session control handle.
* @param x Pointer to a list of x coordinates.
* @param y Pointer to a list of y coordinates.
* @param n Number of doubles in x (assumed the same as in y).
* @param title Title of the plot.
* @return void
*
* Plots out a 2d graph from a list of points. Provide points through a list
* of x and a list of y coordinates. Both provided arrays are assumed to
* contain the same number of values.
*
* @code
* gnuplot_ctrl *h;
* double x[50];
* double y[50];
* int i;
*
* h = gnuplot_init();
* for (i=0; i<50; i++) {
* x[i] = (float)(i)/10.0;
* y[i] = x[i] * x[i];
* }
* gnuplot_plot_xy(h, x, y, 50, "parabola");
* sleep(2);
* gnuplot_close(h);
* @endcode
*/
void gnuplot_plot_xy(gnuplot_ctrl* handle, double* x, double* y,
int n, char* title) {
int i;
int tmpfd;
char name[128];
char cmd[GP_CMD_SIZE];
char line[GP_CMD_SIZE];
if (handle==NULL || x==NULL || y==NULL || (n<1)) return;
/* Open one more temporary file? */
if (handle->ntmp == GP_MAX_TMP_FILES - 1) {
fprintf(stderr,
"maximum # of temporary files reached (%d): cannot open more",
GP_MAX_TMP_FILES);
return;
}
/* Open temporary file for output */
sprintf(name, "%s/gnuplot-i-XXXXXX", P_tmpdir);
if ((tmpfd=mkstemp(name))==-1) {
fprintf(stderr,"cannot create temporary file: exiting plot");
return;
}
/* Store file name in array for future deletion */
strcpy(handle->to_delete[handle->ntmp], name);
handle->ntmp ++;
/* Write data to this file */
for (i=0; i<n; i++) {
sprintf(line, "%f %f\n", x[i], y[i]);
int writeRet = write(tmpfd, line, strlen(line));
if (writeRet == -1)
printf("Error writing data to a file in gnuplot_xy");
}
close(tmpfd);
/* Command to be sent to gnuplot */
if (handle->nplots > 0)
strcpy(cmd, "replot");
else
strcpy(cmd, "plot");
if (title == NULL)
sprintf(line, "%s \"%s\" with %s", cmd, name, handle->pstyle);
else
sprintf(line, "%s \"%s\" title \"%s\" with %s", cmd, name,
title, handle->pstyle);
/* send command to gnuplot */
gnuplot_cmd(handle, line);
handle->nplots++;
return;
}
/**
* @brief Open a new session, plot a signal, close the session.
* @param title Plot title
* @param style Plot style
* @param label_x Label for X
* @param label_y Label for Y
* @param x Array of X coordinates
* @param y Array of Y coordinates (can be NULL)
* @param n Number of values in x and y.
* @return
*
* This function opens a new gnuplot session, plots the provided
* signal as an X or XY signal depending on a provided y, waits for
* a carriage return on stdin and closes the session.
*
* It is Ok to provide an empty title, empty style, or empty labels for
* X and Y. Defaults are provided in this case.
*/
void gnuplot_plot_once(char* title, char* style, char* label_x, char* label_y,
int* x, int* y, int n) {
gnuplot_ctrl* handle;
if (x==NULL || n<1)
return;
if ((handle = gnuplot_init()) == NULL)
return;
if (style!=NULL)
gnuplot_setstyle(handle, style);
else
gnuplot_setstyle(handle, (char*)"lines");
if (label_x!=NULL)
gnuplot_set_xlabel(handle, label_x);
else
gnuplot_set_xlabel(handle, (char*)"X");
if (label_y!=NULL)
gnuplot_set_ylabel(handle, label_y);
else
gnuplot_set_ylabel(handle, (char*)"Y");
if (y==NULL)
gnuplot_plot_x(handle, x, n, title);
else
gnuplot_plot_xy(handle, x, y, n, title);
printf("press ENTER to continue\n");
while (getchar()!='\n') {}
gnuplot_close(handle);
return;
}
/**
* @brief Open a new session, plot a signal, close the session.
* @param title Plot title
* @param style Plot style
* @param label_x Label for X
* @param label_y Label for Y
* @param x Array of X coordinates
* @param y Array of Y coordinates (can be NULL)
* @param n Number of values in x and y.
* @return
*
* This function opens a new gnuplot session, plots the provided
* signal as an X or XY signal depending on a provided y, waits for
* a carriage return on stdin and closes the session.
*
* It is Ok to provide an empty title, empty style, or empty labels for
* X and Y. Defaults are provided in this case.
*/
void gnuplot_plot_once(char* title, char* style, char* label_x, char* label_y,
float* x, float* y, int n) {
gnuplot_ctrl* handle;
if (x==NULL || n<1)
return;
if ((handle = gnuplot_init()) == NULL)
return;
if (style!=NULL)
gnuplot_setstyle(handle, style);
else
gnuplot_setstyle(handle, (char*)"lines");
if (label_x!=NULL)
gnuplot_set_xlabel(handle, label_x);
else
gnuplot_set_xlabel(handle, (char*)"X");
if (label_y!=NULL)
gnuplot_set_ylabel(handle, label_y);
else
gnuplot_set_ylabel(handle, (char*)"Y");