map() / Reference / Processing.org

Name

map()

Description

Re-maps a number from one range to another.

In the first example above, the number 25 is converted from a value in the range of 0 to 100 into a value that ranges from the left edge of the window (0) to the right edge (width).

As shown in the second example, numbers outside the range are not clamped to the minimum and maximum parameters values, because out-of-range values are often intentional and useful.

Examples

size(200, 200);
float value = 25;
float m = map(value, 0, 100, 0, width);
ellipse(m, 200, 10, 10);

float value = 110;
float m = map(value, 0, 100, -20, -10);
println(m);  // Prints "-9.0"

void setup() {
  size(200, 200);
  noStroke();
}

void draw() {
  background(204);
  float  x1 = map(mouseX, 0, width, 50, 150);
  ellipse(x1, 75, 50, 50);  
  float x2 = map(mouseX, 0, width, 0, 200);
  ellipse(x2, 125, 50, 50);  
}

Syntax

map(value, start1, stop1, start2, stop2)

Parameters

value(float)the incoming value to be converted
start1(float)lower bound of the value's current range
stop1(float)upper bound of the value's current range
start2(float)lower bound of the value's target range
stop2(float)upper bound of the value's target range

Return

float

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