add numerical recipes library

lib/nr/ansi/recipes/scrsho.c

@@ -0,0 +1,65 @@
+
+#include <stdio.h>
+#define ISCR 60
+#define JSCR 21
+#define BLANK ' '
+#define ZERO '-'
+#define YY 'l'
+#define XX '-'
+#define FF 'x'
+
+void scrsho(float (*fx)(float))
+{
+	int jz,j,i;
+	float ysml,ybig,x2,x1,x,dyj,dx,y[ISCR+1];
+	char scr[ISCR+1][JSCR+1];
+
+	for (;;) {
+		printf("\nEnter x1 x2 (x1=x2 to stop):\n");
+		scanf("%f %f",&x1,&x2);
+		if (x1 == x2) break;
+		for (j=1;j<=JSCR;j++)
+			scr[1][j]=scr[ISCR][j]=YY;
+		for (i=2;i<=(ISCR-1);i++) {
+			scr[i][1]=scr[i][JSCR]=XX;
+			for (j=2;j<=(JSCR-1);j++)
+				scr[i][j]=BLANK;
+		}
+		dx=(x2-x1)/(ISCR-1);
+		x=x1;
+		ysml=ybig=0.0;
+		for (i=1;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=1-(int) (ysml*dyj);
+		for (i=1;i<=ISCR;i++) {
+			scr[i][jz]=ZERO;
+			j=1+(int) ((y[i]-ysml)*dyj);
+			scr[i][j]=FF;
+		}
+		printf(" %10.3f ",ybig);
+		for (i=1;i<=ISCR;i++) printf("%c",scr[i][JSCR]);
+		printf("\n");
+		for (j=(JSCR-1);j>=2;j--) {
+			printf("%12s"," ");
+			for (i=1;i<=ISCR;i++) printf("%c",scr[i][j]);
+			printf("\n");
+		}
+		printf(" %10.3f ",ysml);
+		for (i=1;i<=ISCR;i++) printf("%c",scr[i][1]);
+		printf("\n");
+		printf("%8s %10.3f %44s %10.3f\n"," ",x1," ",x2);
+	}
+}
+#undef ISCR
+#undef JSCR
+#undef BLANK
+#undef ZERO
+#undef YY
+#undef XX
+#undef FF