Function createMutable

createMutable<T>(
    initialValue: T,
    rowsOrGrid: number | Geometry.Grid,
    columns?: number,
): Geometry.GridArray1d<T>
Creates a GridArray1d instance given the dimensions of the grid. Use createArray if you just want to create an array sized for a grid.

Behind the scenes, it runs:
```
const arr = createArray(initialValue, rows, cols);
return wrapMutable(arr, cols);
```
Type Parameters
- T
Parameters
- initialValue: T
- rowsOrGrid: number | Geometry.Grid
- Optionalcolumns: number
Returns Geometry.GridArray1d<T>