Purpose
Returns a Logical. Returns TRUE if the cell value location (x, y) is valid for the table, and is a null cell (a cell that does not have an assigned value). Returns FALSE if the cell contains a value that is non-null. The GetCellValue() function can be used to retrieve the value.
Syntax
IsGridCellNull( table_id, x_pixel, y_pixel ) table_id is a string representing a table name, a positive integer table number, or 0 (zero). The table must be a grid table.
x_pixel is the integer pixel number of the X coordinate of the grid cell. Pixel numbers start at 0. The maximum pixel value is the (pixel_width-1), determined by calling
RasterTableInfo(...RASTER_TAB_INFO_WIDTH)y_pixel is the integer pixel number of the Y coordinate of the grid cell. Pixel numbers start at 0. The maximum pixel value is the (pixel_height-1), determined by calling
RasterTableInfo(...RASTER_TAB_INFO_HEIGHT).Return Value
A Logical is returned, representing whether the specified cell in the table is null, or non-null. If the grid cell is non-null (IsGridCellNull() returns FALSE), then the GetGridCellValue() function can be called to retrieve the value for that grid pixel.
See Also:
Create Grid statement, GetGridCellValue() function, GridTableInfo(), RasterTableInfo() function