TempleOSTS_140317.ISO

Demo/Graphics/LowPassFilter.CPP

@@ -0,0 +1,82 @@
+#define STEP_SIZE	400
+
+U0 LowPassFilterDemo()
+{
+  F64 y,y1,t,dt;
+  CDC *dc=DCAlias;
+
+  WinMax;
+  DocClear;
+
+  dc->color=BLUE;
+  GrLine(dc,0,0,0,STEP_SIZE);
+  GrLine(dc,0,STEP_SIZE,GR_WIDTH/2,STEP_SIZE);
+  GrLine(dc,GR_WIDTH/2,STEP_SIZE,GR_WIDTH/2,0);
+  GrLine(dc,GR_WIDTH/2,0,GR_WIDTH,0);
+  PressAKey;
+
+  dc->color=CYAN;
+  t=0;
+  y=0.0;
+  while (t<GR_WIDTH) {
+    dt=1.0;
+    if (t<GR_WIDTH/2)
+      y1=STEP_SIZE-STEP_SIZE*Exp(-0.01*t);
+    else
+      y1=STEP_SIZE*Exp(-0.01*(t-GR_WIDTH/2));
+    GrLine(dc,t,y,t+dt,y1);
+    y=y1;
+    t+=dt;
+  }
+  PressAKey;
+
+  dc->color=BLACK;
+  t=0;
+  y=0.0;
+  while (t<GR_WIDTH) {
+    dt=1.0;
+    if (t<GR_WIDTH/2)
+      y1=0.99*y+.01*STEP_SIZE;
+    else
+      y1=0.99*y;
+    GrLine(dc,t,y,t+dt,y1);
+    y=y1;
+    t+=dt;
+  }
+  PressAKey;
+
+  dc->color=RED;
+  t=0;
+  y=0.0;
+  while (t<GR_WIDTH) {
+    dt=Rand/10;
+    if (t<GR_WIDTH/2)
+      y1=LowPass1(.01,y,STEP_SIZE,dt);
+    else
+      y1=LowPass1(.01,y,0,dt);
+    GrLine(dc,t,y,t+dt,y1);
+    y=y1;
+    t+=dt;
+  }
+  PressAKey;
+
+  dc->color=GREEN;
+  t=0;
+  y=0.0;
+  while (t<GR_WIDTH) {
+    dt=Rand/10;
+    if (t<GR_WIDTH/2)
+      y1=LowPass1(.1,y,STEP_SIZE,dt);
+    else
+      y1=LowPass1(.1,y,0,dt);
+    GrLine(dc,t,y,t+dt,y1);
+    y=y1;
+    t+=dt;
+  }
+  PressAKey;
+
+  DCDel(dc);
+  DCFill;
+}
+
+LowPassFilterDemo;