How to Make Raster Conditionals More Efficient

Question

I have a piece of working python code that I am looking to make more efficient. The code is trying to model vegetation change based on 4 rasters containing data on potential evapotranspiration, climate moisture index, precipitation, and summer precipitation. I also have a base vegetation raster that will have its values updated based on a set of conditions depending on values of the 4 rasters above at each cell. I have no idea how to do this without going through the rasters cell by cell because I have to know the cell values for all layers in order for the conditions to work on the cells of the vegetation layer. What is a better way of doing this? Code below: import arcpy import numpy inRasPE = arcpy.Raster("C:/VegModel/CCSSRawData.gdb/pe100Year2") inRasCMI = arcpy.Raster("C:/VegModel/CCSSRawData.gdb/cmi100Year2") inRasPCP = arcpy.Raster("C:/VegModel/CCSSRawData.gdb/pcp100Year2") inRasSPP = arcpy.Raster("C:/VegModel/CCSSRawData.gdb/spp100Year2") #inRasVeg = arcpy.Raster("C:/VegModel/CCSSRawData.gdb/vegnormrs100") #To be used the first time. inRasVeg = arcpy.Raster("C:/VegModel/CCSSRawData.gdb/veg100Year1Revise3") lowerLeft = arcpy.Point(inRasVeg.extent.XMin, inRasVeg.extent.YMin) cellSize = inRasVeg.meanCellWidth inArrayPE = arcpy.RasterToNumPyArray(inRasPE) inArrayCMI = arcpy.RasterToNumPyArray(inRasCMI) inArrayPCP = arcpy.RasterToNumPyArray(inRasPCP) inArraySPP = arcpy.RasterToNumPyArray(inRasSPP) inArrayVeg = arcpy.RasterToNumPyArray(inRasVeg, nodata_to_value = 0) rasHeight, rasWidth = inArrayVeg.shape for i in range(0, rasHeight): for j in range(0, rasWidth): value1 = inArrayPE[i, j] value2 = inArrayVeg[i, j] value3 = inArrayCMI[i, j] if value1 <= 760: if value2 == 11 and value3 < 0: value2 = 21 inArrayVeg[i, j] = value2 elif value2 == 12 and value3 < 0: value2 = 22 inArrayVeg[i, j] = value2 elif value2 == 13 and value3 < 0: value2 = 23 inArrayVeg[i, j] = value2 elif value2 == 14 and value3 < 0: value2 = 24 inArrayVeg[i, j] = value2 elif value2 == 15 and value3 < 0: value2 = 25 inArrayVeg[i, j] = value2 elif value2 == 16 and value3 < 0: value2 = 26 inArrayVeg[i, j] = value2 elif value2 == 21 and value3 < -150: value2 = 41 inArrayVeg[i, j] = value2 elif value2 == 22 and value3 < -150: value2 = 42 inArrayVeg[i, j] = value2 elif value2 == 23 and value3 < -150: value2 = 43 inArrayVeg[i, j] = value2 elif value2 == 24 and value3 < -150: value2 = 44 inArrayVeg[i, j] = value2 elif value2 == 25 and value3 < -40: value2 = 26 inArrayVeg[i, j] = value2 elif value2 == 26 and value3 < -80: value2 = 24 inArrayVeg[i, j] = value2 elif value2 == 31 and value3 < -260: value2 = 41 inArrayVeg[i, j] = value2 elif value2 == 32 and value3 < -260: value2 = 42 inArrayVeg[i, j] = value2 elif value2 == 33 and value3 < -260: value2 = 43 inArrayVeg[i, j] = value2 elif value2 == 34 and value3 < -260: value2 = 44 inArrayVeg[i, j] = value2 elif value2 == 35 and value3 < -220: value2 = 36 inArrayVeg[i, j] = value2 elif value2 == 36 and value3 < -250: value2 = 34 inArrayVeg[i, j] = value2 elif value2 == 41 and value3 < -300: value2 = 51 inArrayVeg[i, j] = value2 elif value2 == 42 and value3 < -300: value2 = 52 inArrayVeg[i, j] = value2 elif value2 == 43 and value3 < -300: value2 = 53 inArrayVeg[i, j] = value2 elif value2 == 44 and value3 < -300: value2 = 54 inArrayVeg[i, j] = value2 elif value2 == 51 and value3 < -400: value2 = 56 inArrayVeg[i, j] = value2 elif value2 == 53 and value3 < -440: value2 = 52 inArrayVeg[i, j] = value2 elif value2 == 54 and value3 < -320: value2 = 53 inArrayVeg[i, j] = value2 elif value2 == 56 and value3 < -440: value2 = 57 inArrayVeg[i, j] = value2 elif value1 > 760: value4 = inArrayPCP[i, j] value5 = inArraySPP[i, j] sixtyThree = -37.298 + (0.027 * value4) + (0.004 * value1) + (70.895 * value5) sixtyFour = -29.53 + (0.001 * value4) + (0.007 * value1) + (79.182 * value5) sixtyFive = -73.987 + (0.002 * value4) + (0.04 * value1) + (114.753 * value5) sixtySix = -67.219 + (0.031 * value4) + (0.017 * value1) + (121.6 * value5) sixtySeven = -190.354 + (0.102 * value4) + (0.023 * value1) + (310.128 * value5) seventyFour = -252.386 + (0.163 * value4) + (0.01 * value1) + (399.599 * value5) isMax = sixtyThree if sixtyFour > isMax: isMax = sixtyFour if sixtyFive > isMax: isMax = sixtyFive if sixtySix > isMax: isMax = sixtySix if sixtySeven > isMax: isMax = sixtySeven if seventyFour > isMax: isMax = seventyFour if value2 == 52 or value2 == 53 or value2 == 54 or value2 == 63 or value2 == 64 or value2 == 65 or value2 == 66 or value2 == 67 or value2 == 74: if isMax == sixtyThree: value2 = 63 inArrayVeg[i, j] = value2 elif isMax == sixtyFour: value2 = 64 inArrayVeg[i,j] = value2 elif isMax == sixtyFive: value2 = 65 inArrayVeg[i, j] = value2 elif isMax == sixtySix: value2 = 66 inArrayVeg[i, j] = value2 elif isMax == sixtySeven: value2 = 67 inArrayVeg[i, j] = value2 elif isMax == seventyFour: value2 = 74 inArrayVeg[i, j] = value2 elif value2 == 11 and value3 < 0: value2 = 21 inArrayVeg[i, j] = value2 elif value2 == 12 and value3 < 0: value2 = 22 inArrayVeg[i, j] = value2 elif value2 == 13 and value3 < 0: value2 = 23 inArrayVeg[i, j] = value2 elif value2 == 14 and value3 < 0: value2 = 24 inArrayVeg[i, j] = value2 elif value2 == 15 and value3 < 0: value2 = 25 inArrayVeg[i, j] = value2 elif value2 == 16 and value3 < 0: value2 = 26 inArrayVeg[i, j] = value2 elif value2 == 21 and value3 < -150: value2 = 41 inArrayVeg[i, j] = value2 elif value2 == 22 and value3 < -150: value2 = 42 inArrayVeg[i, j] = value2 elif value2 == 23 and value3 < -150: value2 = 43 inArrayVeg[i, j] = value2 elif value2 == 24 and value3 < -150: value2 = 44 inArrayVeg[i, j] = value2 elif value2 == 25 and value3 < -40: value2 = 26 inArrayVeg[i, j] = value2 elif value2 == 26 and value3 < -80: value2 = 24 inArrayVeg[i, j] = value2 elif value2 == 31 and value3 < -260: value2 = 41 inArrayVeg[i, j] = value2 elif value2 == 32 and value3 < -260: value2 = 42 inArrayVeg[i, j] = value2 elif value2 == 33 and value3 < -260: value2 = 43 inArrayVeg[i, j] = value2 elif value2 == 34 and value3 < -260: value2 = 44 inArrayVeg[i, j] = value2 elif value2 == 35 and value3 < -220: value2 = 36 inArrayVeg[i, j] = value2 elif value2 == 36 and value3 < -250: value2 = 34 inArrayVeg[i, j] = value2 elif value2 == 41 and value3 < -300: value2 = 51 inArrayVeg[i, j] = value2 elif value2 == 42 and value3 < -300: value2 = 52 inArrayVeg[i, j] = value2 elif value2 == 43 and value3 < -300: value2 = 53 inArrayVeg[i, j] = value2 elif value2 == 44 and value3 < -300: value2 = 54 inArrayVeg[i, j] = value2 elif value2 == 51 and value3 < -400: value2 = 56 inArrayVeg[i, j] = value2 elif value2 == 56 and value3 < -440: value2 = 57 inArrayVeg[i, j] = value2 newRaster = arcpy.NumPyArrayToRaster(inArrayVeg, lowerLeft, cellSize, value_to_nodata = 0) newRaster.save("C:/VegModel/Revise.gdb/veg100Year2Revise3")‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍

DanPatterson_Retired · Answer

Come up with a list of your conditions in a matrix form In the interim, work through the logic in this example of how to work with conditional statements in numpy. I have presented this as verbosely as possible using np functions rather than shortcuts. Once you understand the workflow I can show the shortcuts... >>> a = np.arange(36).reshape(6,6) >>> b = np.where(a % 2 == 0, a, np.random.randint(36)) >>> c = np.where(a < 18, a, np.random.randint(36)) >>> a array([[ 0, 1, 2, 3, 4, 5], [ 6, 7, 8, 9, 10, 11], [12, 13, 14, 15, 16, 17], [18, 19, 20, 21, 22, 23], [24, 25, 26, 27, 28, 29], [30, 31, 32, 33, 34, 35]]) >>> b array([[ 0, 34, 2, 34, 4, 34], [ 6, 34, 8, 34, 10, 34], [12, 34, 14, 34, 16, 34], [18, 34, 20, 34, 22, 34], [24, 34, 26, 34, 28, 34], [30, 34, 32, 34, 34, 34]]) >>> c array([[ 0, 1, 2, 3, 4, 5], [ 6, 7, 8, 9, 10, 11], [12, 13, 14, 15, 16, 17], [27, 27, 27, 27, 27, 27], [27, 27, 27, 27, 27, 27], [27, 27, 27, 27, 27, 27]]) >>> d = np.logical_and(a > 15, b ==34) >>> d array([[0, 0, 0, 0, 0, 0], [0, 0, 0, 0, 0, 0], [0, 0, 0, 0, 0, 1], [0, 1, 0, 1, 0, 1], [0, 1, 0, 1, 0, 1], [0, 1, 0, 1, 1, 1]], dtype=bool) >>> e = np.logical_or(c > 15, b !=34) >>> e array([[1, 0, 1, 0, 1, 0], [1, 0, 1, 0, 1, 0], [1, 0, 1, 0, 1, 1], [1, 1, 1, 1, 1, 1], [1, 1, 1, 1, 1, 1], [1, 1, 1, 1, 1, 1]], dtype=bool) >>> >>> final = np.where(d+e==0,5,np.where(d+e==1,6,7)) >>> final array([[6, 5, 6, 5, 6, 5], [6, 5, 6, 5, 6, 5], [6, 5, 6, 5, 6, 6], [6, 6, 6, 6, 6, 6], [6, 6, 6, 6, 6, 6], [6, 6, 6, 6, 6, 6]]) ‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍ Good luck