Tag Archives: gradient

Plotting with Calcpad 3.2

The new and enhanced version of Calcpad 3.2 was released. Besides other improvements, we added some nice visual effects for 2D plotting.

In general, you can use Calcpad to plot functions of two parameters f(x; y), by the $Map command:

$Map{f(x;y) @ x = a : b & y = c : d}

The result is displayed as a 2D contour map. For example, let us take the function:

f(x; y) = cos(x) + cos(y) + cos(π/2*sqr(x^2 + y^2))

The $Map command will produce the following image:

The left one is without shadow effects. Different values of the function are represented by the respective colors. Blues are the lowest and reds are the highest. However, you need to have quite a rich imagination to figure out how the surface actually looks. That is why we added a 3D shadows effects. On the right side, you can see the same image, but with shadows. The light here comes from North-West direction. Now it looks much more natural and it is easier for the human eye to perceive the shape.

The shading is calculated using the dot product of the normal vector to the surface by the vector of the light.

There are also other plotting options available:

Toolbar

You can select among different color scales:

If you select “smooth” (gradient) scale, you will get the following image:

Gradient map with shadows

Instead of having contours, now the colors flow smoothly from one to another. That is because the color of each pixel is calculated individually based on its value.

Download the latest version of Calcpad 3.2 and try by yourself:

http://calcpad.net/download/calcpad-setup.exe