3d sonogram with GLSL shader

Hello !

I'm trying to create a 3d sonogram that would display sound as a plane of concentric circles.

I'm now trying to create a matrix containing my amplitude values as polar coordinates, with a jit.gl.slab and a GLSL shader.
I found a snippet of code there which does just that and I adapted it, but I get the errors :
ERROR: 2:24 : " : Illegal non-ASCII character(0x96)
ERROR: 2:24 : 'Center' : Syntax error syntax error
And the shader can't compile.

Here is the code of my shader:

<jittershader name="default">
    <description>Default Slab </description>
    <param name="scale" type="float" default="1.0" />
    <param name="tex0" type="int" default="0" />
    <param name="modelViewProjectionMatrix" type="mat4" state="MODELVIEW_PROJECTION_MATRIX" />
    <param name="textureMatrix0" type="mat4" state="TEXTURE0_MATRIX" />
    <param name="position" type="vec3" state="POSITION" />
    <param name="texcoord" type="vec2" state="TEXCOORD" />

    <language name="glsl" version="1.5">

        <bind param="scale" program="fp" />
        <bind param="tex0" program="fp" />
        <bind param="modelViewProjectionMatrix" program="vp" />
        <bind param="textureMatrix0" program="vp" />
        <bind param="position" program="vp" />
        <bind param="texcoord" program="vp" />

        <program name="vp" type="vertex"  >
        <![CDATA[
            #version 330 core

in vec3 position;
in vec2 texcoord;
out jit_PerVertex {
vec2 texcoord;
            } jit_out;
out vec2 jit_textCoord;
uniform mat4 modelViewProjectionMatrix;
uniform mat4 textureMatrix0;

void main(void) {
gl_Position = modelViewProjectionMatrix*vec4(position, 1.);
                jit_out.texcoord = vec2(textureMatrix0*vec4(texcoord, 0., 1.));
                jit_textCoord = jit_out.texcoord;
            }
        ]]>
        </program>

        <program name="fp" type="fragment"  >
        <![CDATA[
            #version 330 core

in vec2 jit_textCoord;

// Control inputs
uniform float Angle; // range 2pi / 100000.0 to 1.0 (rounded down), exponential
uniform float AngleMin; // range -3.2 to 3.2
uniform float AngleWidth; // range 0.0 to 6.4
uniform float Radius; // range -10000.0 to 1.0
uniform float RadiusMin; // range 0.0 to 2.0
uniform float RadiusWidth; // range 0.0 to 2.0
uniform vec2 Center; // range: -1.0 to 3.0

layout (location = 0) out vec4 outColor;

// Texture input
uniform sampler2D Texture;

void main()
{
// Normalised texture coords
vec2 texCoord = jit_textCoord.xy;
// Shift origin to texture centre (with offset)
vec2 normCoord;
normCoord.x = 2.0 * texCoord.x – Center.x;
normCoord.y = 2.0 * texCoord.y – Center.y;
// Convert Cartesian to Polar coords
float r = length(normCoord);
float theta = atan(normCoord.y, normCoord.x);

// The actual effect
r = (r < RadiusMin) ? r : (r > RadiusMin + RadiusWidth) ? r : ceil(r / Radius) * Radius;
theta = (theta < AngleMin) ? theta : (theta > AngleMin + AngleWidth) ? theta : floor(theta / Angle) * Angle;

// Convert Polar back to Cartesian coords
normCoord.x = r * cos(theta);
normCoord.y = r * sin(theta);
// Shift origin back to bottom-left (taking offset into account)
texCoord.x = normCoord.x / 2.0 + (Center.x / 2.0);
texCoord.y = normCoord.y / 2.0 + (Center.y / 2.0);

// Output
outColor = texture2D(Texture, texCoord);
}
        ]]>
        </program>
    </language>
</jittershader>

Has anyone ever encountered those errors ? How can I correct them ?

Thanks !