Impl set_cross

src/plot.rs

@@ -812,6 +812,14 @@ impl Plot {
         self.set_frame_border(show_all, show_all, show_all, show_all)
     }
 
+    /// Draws infinite lines at x=0 and y=0
+    pub fn set_cross(&mut self, color: &str, line_style: &str, line_width: f64) -> &mut Self {
+        let opt = format!(",color='{}',linestyle='{}',linewidth={}", color, line_style, line_width);
+        self.buffer
+            .push_str(&format!("plt.axhline(0{})\nplt.axvline(0{})\n", &opt, &opt));
+        self
+    }
+
     /// Writes extra python commands
     pub fn extra(&mut self, commands: &str) -> &mut Self {
         self.buffer.write_str(commands).unwrap();
@@ -1259,4 +1267,13 @@ mod tests {
                        plt.gca().set_zlabel(r'Z')\n";
         assert_eq!(plot.buffer, b);
     }
+
+    #[test]
+    fn extra_functionality_works() {
+        let mut plot = Plot::new();
+        plot.set_cross("red", "--", 3.0);
+        let b: &str = "plt.axhline(0,color='red',linestyle='--',linewidth=3)\n\
+                       plt.axvline(0,color='red',linestyle='--',linewidth=3)\n";
+        assert_eq!(plot.buffer, b);
+    }
 }

tests/test_plot.rs

@@ -300,3 +300,22 @@ fn test_plot_multiple_of_pi() -> Result<(), StrError> {
     assert!(lines_iter.count() > 1060);
     Ok(())
 }
+
+#[test]
+fn test_plot_extra_functionality() -> Result<(), StrError> {
+    // plot
+    let mut plot = Plot::new();
+    plot.set_cross("red", "--", 3.0).set_range(-1.0, 1.0, -1.0, 1.0);
+
+    // save figure
+    let path = Path::new(OUT_DIR).join("integ_plot_extra_functionality.svg");
+    plot.set_show_errors(true).save(&path)?;
+
+    // check number of lines
+    let file = File::open(path).map_err(|_| "cannot open file")?;
+    let buffered = BufReader::new(file);
+    let lines_iter = buffered.lines();
+    let n = lines_iter.count();
+    assert!(n > 480 && n < 520);
+    Ok(())
+}