Number format in French

I'm tring to change the number format of my result in my view but i have a problem.

It's shows me A non well formed numeric value encountered

My code below

<td style="font-size:60%">
<?php
$val = $indemnite->indemnite;

 // Notation française
$resultat = number_format($val, 2, ',', ' ');
// Résultat : 1 234,56
echo $resultat ;
?>
</td>

via Chebli Mohamed