Several implementations on math expression block

1 files changed, 55 insertions, 0 deletions

diff --git a/Project/fparser/examples/example.cc b/Project/fparser/examples/example.cc
new file mode 100644
index 0000000..2d6b771
--- /dev/null
+++ b/Project/fparser/examples/example.cc
@@ -0,0 +1,55 @@
+// Simple example file for the function parser
+// ===========================================
+
+/* When running the program, try for example with these values:
+
+f(x) = x^2
+min x: -5
+max x: 5
+step: 1
+
+*/
+
+#include "../fparser.hh"
+
+#include <iostream>
+#include <string>
+
+int main()
+{
+    std::string function;
+    double minx, maxx, step;
+    FunctionParser fparser;
+
+    fparser.AddConstant("pi", 3.1415926535897932);
+
+    while(true)
+    {
+        std::cout << "f(x) = ";
+        std::getline(std::cin, function);
+        if(std::cin.fail()) return 0;
+
+        int res = fparser.Parse(function, "x");
+        if(res < 0) break;
+
+        std::cout << std::string(res+7, ' ') << "^\n"
+                  << fparser.ErrorMsg() << "\n\n";
+    }
+
+    std::cout << "min x: ";
+    std::cin >> minx;
+    std::cout << "max x: ";
+    std::cin >> maxx;
+    std::cout << "step: ";
+    std::cin >> step;
+    if(std::cin.fail()) return 0;
+
+    double vals[] = { 0 };
+    for(vals[0] = minx; vals[0] <= maxx; vals[0] += step)
+    {
+        std::cout << "f(" << vals[0] << ") = " << fparser.Eval(vals)
+                  << std::endl;
+    }
+
+    return 0;
+}