# norminv

Computes the norm of a vector on the down scaled region of interest.

## Contents

- Syntax
- Description
- See Also
- Code

## Syntax

    n = norminv(x,seti)

## Description

`n = norminv(x,seti)` does the same as `normroi` for down scaled region of interest, i.e. scaling factor `seti.dVinv` instead `seti.dVinv`.

## See Also

- setGridScale.html
- normroi.html

## Code

    function n = norminv(x,seti)
    % uses seti.qNorm and seti.dVinv

    Q = seti.qNorm;
    dV = seti.dVinv;

    if Q == 2
        n = sqrt(abs(innerinv(x,x,seti)));
    else
        n = norm(x,Q)*dV^(1/Q); % in case Q = 2 the result is the same like above
    end

    end