View Compilation Error

0_0_24257654_12763.c: In function 'main':
0_0_24257654_12763.c:19:3: error: 'for' loop initial declarations are only allowed in C99 or C11 mode
   for (int i = 0; i < N; i++) {
   ^
0_0_24257654_12763.c:19:3: note: use option -std=c99, -std=gnu99, -std=c11 or -std=gnu11 to compile your code
0_0_24257654_12763.c:22:3: error: 'for' loop initial declarations are only allowed in C99 or C11 mode
   for (double theta =  - PI / 2; theta < PI / 2; theta += 0.01) {
   ^
0_0_24257654_12763.c:24:4: error: 'for' loop initial declarations are only allowed in C99 or C11 mode
    for (int i = 0; i < N; i++) {
    ^