CODEWITHSUNDEEP
c++normalization
anti
anti

Reputation: 3145

Normalize a negative or positive number between -1 and 1?

I have streaming data, as float values that range between -2 and +4. I need to write a function that normalizes these values between -1 and +1.

I have:

float normalize(float input)
{
    int min = -1;
    int max = 1;
    float normalized_x = (input - min) / (max - min);
    return normalized_x;
}

But this gives me values that are incorrect, and range from -0.4 to +2.3, roughly. What do I need to adjust in my function?

Thank you.

Upvotes: 2

Views: 11500

Answers (1)

Iluvatar
Iluvatar

Reputation: 1537

You want to first center the range around 0, then divide to make it go from -1 to 1.

float normalize(float input)
{
    float normalized_x = (input - 1) / 3;
    return normalized_x;
}

More generalized:

const float min = -2;
const float max = 4;
float normalize(float input)
{
    float average      = (min + max) / 2;
    float range        = (max - min) / 2;
    float normalized_x = (input - average) / range;
    return normalized_x;
}

Upvotes: 10

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