map()

[Math]

double map(double x, double in_min, double in_max, double out_min, double out_max);

Description

Maps the value of x from the range of in_min to in_max to the range of out_min to out_max.

Parameters

x: the value to be mapped.

in_min: the minimum value of the input range.

in_max: the maximum value of the input range.

out_min: the minimum value of the output range.

out_max: the maximum value of the output range.

Returns

The mapped value of x.

Example Code

The code reads the value of a potentiometer connected to pin IN and place the cosine value mapped to the pin OUT.

void setup() {
    pinLabel(0, "IN");   // set the label of pin 0 to "IN"
    pinLabel(1, "OUT");  // set the label of pin 1 to "OUT"
    pinMode(1, OUTPUT);  // set pin 1 as output
    
    pinLabel(2, "VCC");  // set the label of pin 2 to "VCC"
    powerPin(2);         // set pin 2 as power pin
    pinLabel(3, "GND");  // set the label of pin 3 to "GND"
    groundPin(3);        // set pin 3 as ground pin
}

void loop() {
    // read the value of the potentiometer
    int val = analogRead(0); 
    // map the value to the range of 0 to 360
    double angle = map(val, 0, 1023, 0, 360);
    // calculate the cosine of the angle in radians
    double cosVal = cos(angle * PI / 180);
    // map the value to the range of 0 to 1023
    analogWrite(1, cosVal * 1023);
    // delay for 100ms
    delay(100);
}

double map(double x, double in_min, double in_max, double out_min, double out_max) {
    // maps the value of x from the range of in_min 
    // to in_max to the range of out_min to out_max
    return (x - in_min) * (out_max - out_min) / (in_max - in_min) + out_min;
}