add numerical recipes library

lib/nr/cpp/recipes/scrsho.cpp

@@ -0,0 +1,55 @@
+#include <string>
+#include <iostream>
+#include <iomanip>
+#include "nr.h"
+using namespace std;
+
+void NR::scrsho(DP fx(const DP))
+{
+	const int ISCR=60, JSCR=21;
+	const char BLANK=' ', ZERO='-', YY='l', XX='-', FF='x';
+	int jz,j,i;
+	DP ysml,ybig,x2,x1,x,dyj,dx;
+	Vec_DP y(ISCR);
+	string scr[JSCR];
+
+	for (;;) {
+		cout << endl << "Enter x1 x2 (x1=x2 to stop):" << endl;
+		cin >> x1 >> x2;
+		if (x1 == x2) break;
+		scr[0]=YY;
+		for (i=1;i<(ISCR-1);i++)
+			scr[0] += XX;
+		scr[0] += YY;
+		for (j=1;j<(JSCR-1);j++) {
+			scr[j]=YY;
+			for (i=1;i<(ISCR-1);i++)
+				scr[j] += BLANK;
+			scr[j] += YY;
+		}
+		scr[JSCR-1]=scr[0];
+		dx=(x2-x1)/(ISCR-1);
+		x=x1;
+		ysml=ybig=0.0;
+		for (i=0;i<ISCR;i++) {
+			y[i]=fx(x);
+			if (y[i] < ysml) ysml=y[i];
+			if (y[i] > ybig) ybig=y[i];
+			x += dx;
+		}
+		if (ybig == ysml) ybig=ysml+1.0;
+		dyj=(JSCR-1)/(ybig-ysml);
+		jz=int(-ysml*dyj);
+		for (i=0;i<ISCR;i++) {
+			scr[jz][i]=ZERO;
+			j=int((y[i]-ysml)*dyj);
+			scr[j][i]=FF;
+		}
+		cout << fixed << setprecision(3);
+		cout << setw(11) << ybig << " " << scr[JSCR-1] << endl;
+		for (j=JSCR-2;j>=1;j--)
+			cout << "            " << scr[j] << endl;
+		cout << setw(11) << ysml << " " << scr[0] << endl;
+		cout << setw(19) << x1 << setw(55) << x2;
+	}
+}