Initializing struct with union of arrays

Question

I noticed there have been many posts about this subject but I cannot seem to pin point anything that would help.

I have defined the following code:

typedef struct
{
    float re;
    float im;
} MyComplex;

typedef struct
{
    float rf;
    union
    {
        float     noise[4];
        MyComplex iq[4];
    };
} RfTable_t;

RfTable_t Noise[2] = 
{
    { 1.2f, .noise=0.f },
    { 2.1f, .noise=0.f };
};

**EDIT - Add function Test**

void Test()
{
    Noise[0].rf = 2.1f;
    Noise[0].noise[0] = 3.2f;
}

I am trying to define the global variable Noise statically. I get the following error:

   expected primary expression before '{' token
   expected primary expression before '{' token
   expected primary expression before '}' before '{' token
   expected primary expression before '}' before '{' token
   expected primary expression before ',' or ';' before '{' token
   expected declaration before '}' token

Answer 1

Any structure, union, and/or array to be initialized needs its own set of curly braces to initialize it. Specifically, the union needs a set of braces, and the float array inside the union also needs braces:

RfTable_t Noise[2] =
{
    { 1.2f, { .noise={0.f} } },
    { 2.1f, { .noise={0.f} } }
};

Note also that you had a stray ; inside of the initializer.

Answer 2

I made the smallest changes I could to make it compile:

#include <stdio.h>

typedef struct
{
    float re;
    float im;
} MyComplex;

typedef struct
{
    float rf;
    union
    {
        float     noise[4];
        MyComplex iq[4];
    };
} RfTable_t;

RfTable_t Noise[2] = 
{
    { 1.2f, .noise={0.f} },  // Initialize NOISE with {0.f} instead of 0.f.
    { 2.1f, .noise={0.f} }   // Remove extra semi-colon.
};


int main(void) {
    return 0;
}

Clean Compile:

https://ideone.com/pvI9Ci

In brief:
noise is an array.
To initialize it you must use the array initializer syntax:
{ value, value, value }

You did not have brackets around your value of 0.f .

Also, you had an extra semi-colon.