ckplot

commit c6adc9093fb429480d8a752308eac1b626f45957
Author: aabacchus <ben@bvnf.space>
Date:   Sun,  3 Oct 2021 00:26:03 +0100

kplot: plot scatter graphs using kplot(3) and csv(3)

Diffstat:
A
.gitignore
 | 
3
+++
A
Makefile
 | 
12
++++++++++++
A
kplot.c
 | 
87
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

3 files changed, 102 insertions(+), 0 deletions(-)
diff --git a/.gitignore b/.gitignore
@@ -0,0 +1,3 @@
+kplot
+*.pdf
+*.csv
diff --git a/Makefile b/Makefile
@@ -0,0 +1,12 @@
+.POSIX:
+
+XCFLAGS = $(CFLAGS) -I/usr/local/include -I/usr/include/cairo -Wall -Wextra -Wpedantic
+XLDFLAGS = $(LDFLAGS) -lkplot -L/usr/local/lib -lcsv -lcairo
+
+kplot: kplot.c
+	$(CC) $(XCFLAGS) $(XLDFLAGS) -o $@ $<
+
+clean:
+	rm -f kplot
+
+.PHONY: clean
diff --git a/kplot.c b/kplot.c
@@ -0,0 +1,87 @@
+#include <bsd/stdio.h>
+#include <bsd/stdlib.h>
+#include <cairo.h>
+#include <cairo-pdf.h>
+#include <csv.h>
+#include <kplot.h>
+#include <math.h>
+#include <unistd.h>
+
+void
+usage(char *argv0) {
+    fprintf(stderr, "usage: %s [-H] file.csv\n", argv0);
+    fprintf(stderr, "    -H    treat first line as header\n");
+}
+
+int
+main(int argc, char **argv) {
+    int ch, flag_H;
+    flag_H = 0;
+    while ((ch = getopt(argc, argv, "H")) != -1) {
+        switch (ch) {
+            case 'H':
+                flag_H = 1;
+                break;
+            case '?':
+                usage(*argv);
+                return 1;
+        }
+    }
+
+    if (argc - optind == 0) {
+        usage(*argv);
+        return 1;
+    }
+
+    argv += optind;
+
+    FILE *f = fopen(*argv, "r");
+    if (f == NULL) {
+        perror(*argv);
+        return 1;
+    }
+
+    struct csv *c = csv_create();
+    if (csv_read_file(f, c, flag_H) != 0) {
+        perror("csv_read_file");
+        return 1;
+    }
+    if (c->cols != 2) {
+        fprintf(stderr, "%d columns - what should be plotted?\n", c->cols);
+        csv_destroy(c);
+        return 1;
+    }
+    if (c->rows < 1) {
+        fprintf(stderr, "no rows found\n");
+        csv_destroy(c);
+        return 1;
+    }
+
+    int rows = c->rows;
+    struct kpair points1[c->rows];
+
+    for (int i = 0; i < c->rows; i++) {
+        points1[i].x = c->data[i][0];
+        points1[i].y = c->data[i][1];
+    }
+    csv_destroy(c);
+
+    struct kdata *d1;
+    struct kplot *p;
+    cairo_surface_t *surf;
+    cairo_t *cr;
+
+    d1 = kdata_array_alloc(points1, rows);
+    p = kplot_alloc(NULL);
+    kplot_attach_data(p, d1, KPLOT_POINTS, NULL);
+    kdata_destroy(d1);
+    //surf = cairo_image_surface_create(CAIRO_FORMAT_ARGB32, 600, 400);
+    surf = cairo_pdf_surface_create("out.pdf", 600, 400);
+    cr = cairo_create(surf);
+    cairo_surface_destroy(surf);
+    kplot_draw(p, 600.0, 400.0, cr);
+    //cairo_surface_write_to_png(cairo_get_target(cr), "example0.png");
+    cairo_destroy(cr);
+    kplot_free(p);
+    return 0;
+}