sample.go

func GenerateESRIASC(data *input) {
	f, err := os.Create("/tmp/esri.asc")
	if err != nil {
		fmt.Println(err)
		return
	}
	defer f.Close()

	yBottom := (data.FirstRowStartLine - data.IntervalBetweenColumns*(float32(data.NumberOfRowsInField)-1.0))

	f.WriteString(fmt.Sprintf("ncols          %d\n", data.NumberOfColumsInField))
	f.WriteString(fmt.Sprintf("nrows          %d\n", data.NumberOfRowsInField))
	f.WriteString(fmt.Sprintf("xllcenter      %f\n", data.FirstPointFirstRow))
	f.WriteString(fmt.Sprintf("yllcenter      %f\n", yBottom))
	f.WriteString(fmt.Sprintf("cellsize       %f\n", data.IntervalBetweenColumns))
	f.WriteString(fmt.Sprintf("nodata_value   %f\n", data.Float32MissingDataValue))

	log.Println(data.NumberOfRowsInField, "rows")
	log.Println(data.NumberOfColumsInField, "columns")
	log.Println(data.IntervalBetweenColumns, "pixel size")

	numRows := int(data.NumberOfRowsInField)
	numCols := int(data.NumberOfColumsInField)

	for i := 0; i < numRows; i++ {
		for j := 0; j < numCols-1; j++ {
			f.WriteString(fmt.Sprintf("%d ", data.DataBlock[i*numCols+j]))
		}
		f.WriteString(fmt.Sprintf("%d\n", data.DataBlock[i*numCols+numCols-1]))
	}

}