Reference for Wiring version 0023+. If you have a previous version, use the reference included with your software. If you see any errors or have any comments, let us know.

Name

map()
Examples 
int value;
int m;

void setup() {
  Serial.begin(9600);
}

void loop() {
  value = analogRead(0);
  m = (int)map(value, 0, 1023, 0, 255); // converts a number in the range
  Serial.println(m, BYTE);              // 0-1023 to a number in the range 0-255
  delay(100);
}
Description Re-maps a number from one range to another. In the example above, the number value is converted from a value in the range 0..1023 into a value that ranges from 0 to 255.

Numbers outside the range are not clamped to 0 and 1, because out-of-range values are often intentional and useful.
Syntax 
map(value, low1, high1, low2, high2)
Parameters
value float: The incoming value to be converted
low1 float: Lower bound of the value's current range
high1 float: Upper bound of the value's current range
low2 float: Lower bound of the value's target range
high2 float: Upper bound of the value's target range
Returns float
Usage Application
Updated on November 01, 2009 12:47:23pm PST

Creative Commons License