C语言绘制ROC曲线：代码示例与解释

以下是一个使用C语言绘制ROC曲线的示例代码：\n\nc\n#include <stdio.h>\n#include <stdlib.h>\n#include <math.h>\n\n// 计算真正例率（True Positive Rate）\ndouble calculateTPR(int TP, int FN) {\n return (double)TP / (TP + FN);\n}\n\n// 计算假正例率（False Positive Rate）\ndouble calculateFPR(int FP, int TN) {\n return (double)FP / (FP + TN);\n}\n\n// 绘制ROC曲线\nvoid drawROC(double* TPR, double* FPR, int numPoints) {\n FILE* gnuplot = popen("gnuplot -persist", "w"); // 打开gnuplot进程\n if (gnuplot == NULL) {\n fprintf(stderr, "Error opening gnuplot\n");\n return;\n }\n \n // 绘制ROC曲线\n fprintf(gnuplot, "set title 'ROC Curve'\n");\n fprintf(gnuplot, "set xlabel 'False Positive Rate'\n");\n fprintf(gnuplot, "set ylabel 'True Positive Rate'\n");\n fprintf(gnuplot, "plot '-' with lines\n");\n for (int i = 0; i < numPoints; i++) {\n fprintf(gnuplot, "%lf %lf\n", FPR[i], TPR[i]);\n }\n fprintf(gnuplot, "e\n");\n \n // 关闭gnuplot进程\n pclose(gnuplot);\n}\n\nint main() {\n int numPoints = 100;\n double* TPR = (double*)malloc(numPoints * sizeof(double));\n double* FPR = (double*)malloc(numPoints * sizeof(double));\n \n // 生成随机的TPR和FPR数据\n for (int i = 0; i < numPoints; i++) {\n TPR[i] = rand() / (double)RAND_MAX;\n FPR[i] = rand() / (double)RAND_MAX;\n }\n \n // 绘制ROC曲线\n drawROC(TPR, FPR, numPoints);\n \n free(TPR);\n free(FPR);\n \n return 0;\n}\n\n\n该代码使用了gnuplot库来绘制ROC曲线，因此在编译和运行之前需要确保已经安装了gnuplot。代码首先生成了随机的TPR和FPR数据，然后调用drawROC函数绘制ROC曲线。绘制的结果会在一个新的窗口中显示出来。\n\n