- /**
- * Method for drawing a positive cosine curve on an image
- * Edit: bbs.it-home.org
- */
- Define ("MAX_WIDTH_PIXEL", 600 );
- Define ("MAX_HEIGHT_PIXEL", 240 );
- // Send the header information
- Header ("Content-type: image/gif ");
- // Create an image
- $ Img = imageCreate (MAX_WIDTH_PIXEL, MAX_HEIGHT_PIXEL );
- // Set the color
- $ Bgcolor = imageColorAllocate ($ img, 0xff, 0xe9, 0xe9 );
- $ Red = imageColorAllocate ($ img, 255, 0, 0 );
- $ Blue = imageColorAllocate ($ img, 0, 0,255 );
- $ Brown = imageColorAllocate ($ img, 100, 0, 0 );
- $ Black = imageColorAllocate ($ img, 0, 0, 0 );
- $ Width = MAX_WIDTH_PIXEL/2; // width
- $ Height = MAX_HEIGHT_PIXEL/2; // height
- // Create an axis
- ImageLine ($ img, $ width, 0, $ width, MAX_HEIGHT_PIXEL, $ black); // Y axis
- ImageLine ($ img, 0, $ height, MAX_WIDTH_PIXEL, $ height, $ black); // x axis
- // Use loops to depict function images
- For ($ I = 0; $ I <= MAX_WIDTH_PIXEL; $ I ++)
- {
- $ Y1 = 100 * sin ($ I/100 * M_PI );
- ImageSetPixel ($ img, $ I, $ height + $ y1, $ blue );
- $ Y2 = 100 * sin ($ I/300 * M_PI );
- ImageSetPixel ($ img, $ I, $ height + $ y2, $ red );
- $ Y3 = 100 * sin ($ I/300 * M_PI );
- ImageSetPixel ($ img, $ I, $ height-$ y3, $ brown );
- }
- // Display the image
- ImageGif ($ img );
- // Release resources
- ImageDestroy ($ img );
- ?>
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