Initial entry of plot_3vars_savefig.py for having matplotlib create an image file containing the plot

plot_3vars_savefig.py

@@ -0,0 +1,69 @@
+"""
+
+E. Wes Bethel, Copyright (C) 2022
+
+October 2022
+
+Description: This code loads a .csv file and creates a 3-variable plot, and saves it to a file named "myplot.png"
+
+Inputs: the named file "sample_data_3vars.csv"
+
+Outputs: displays a chart with matplotlib
+
+Dependencies: matplotlib, pandas modules
+
+Assumptions: developed and tested using Python version 3.8.8 on macOS 11.6
+
+"""
+
+import pandas as pd
+import matplotlib.pyplot as plt
+
+plot_fname = "myplot.png"
+
+fname = "sample_data_3vars.csv"
+df = pd.read_csv(fname, comment="#")
+print(df)
+
+var_names = list(df.columns)
+
+print("var names =", var_names)
+
+# split the df into individual vars
+# assumption: column order - 0=problem size, 1=blas time, 2=basic time
+
+problem_sizes = df[var_names[0]].values.tolist()
+code1_time = df[var_names[1]].values.tolist()
+code2_time = df[var_names[2]].values.tolist()
+code3_time = df[var_names[3]].values.tolist()
+
+plt.figure()
+
+plt.title("Comparison of 3 Codes")
+
+xlocs = [i for i in range(len(problem_sizes))]
+
+plt.xticks(xlocs, problem_sizes)
+
+plt.plot(code1_time, "r-o")
+plt.plot(code2_time, "b-x")
+plt.plot(code3_time, "g-^")
+
+#plt.xscale("log")
+#plt.yscale("log")
+
+plt.xlabel("Problem Sizes")
+plt.ylabel("runtime")
+
+varNames = [var_names[1], var_names[2], var_names[3]]
+plt.legend(varNames, loc="best")
+
+plt.grid(axis='both')
+
+# save the figure before trying to show the plot
+plt.savefig(plot_fname, dpi=300)
+
+
+plt.show()
+
+# EOF