eigen example

Cryoris · Cryoris · commit 0805e32b61ca · 2019-06-10T11:35:39.000+02:00
diff --git a/examples/eigen/basic.cpp b/examples/eigen/basic.cpp
@@ -0,0 +1,45 @@
+#define _USE_MATH_DEFINES
+#include "../../matplotlibcpp.h"
+#include <Eigen/Dense>
+#include <cmath>
+#include <iostream>
+
+namespace plt = matplotlibcpp;
+
+int main() {
+  // Prepare data.
+  int n = 5000;
+  Eigen::VectorXd x(n), y(n), z(n), w = 2 * Eigen::VectorXd::Ones(n);
+  for (int i = 0; i < n; ++i) {
+    x(i) = i * i;
+    y(i) = sin(2 * M_PI * i / 360.0);
+    z(i) = log(i);
+  }
+
+  // Set the size of output image = 1200x780 pixels
+  plt::figure_size(1200, 780);
+
+  // Plot line from given x and y data. Color is selected automatically.
+  plt::plot(x, y);
+
+  // Plot a red dashed line from given x and y data.
+  plt::plot(x, w, "r--");
+
+  // Plot a line whose name will show up as "log(x)" in the legend.
+  plt::plot(x, z, {{"label", "log(x)"}});
+
+  // Set x-axis to interval [0,1000000]
+  plt::xlim(0, 1000 * 1000);
+
+  // Add graph title
+  plt::title("Sample figure");
+
+  // Enable legend.
+  plt::legend();
+
+  // save figure
+  const char *filename = "./basic.png";
+  std::cout << "Saving result to " << filename << std::endl;
+
+  plt::save(filename);
+}
