使用函数进行GIS成本计算

Question

我想计算由值1和2组成的两个栅格图层（ramdom，模拟）的成本，第一个是随机创建的，第二个是使用两个相关的成本图层进行优化。代码看起来有点像下面。但是，我无法使该功能读取我的第二个光栅。

driver1 = gdal.GetDriverByName ('RST')
driver1.Register ()
ready = gdal.Open ('ramdom.rst', gdal.GDT_Byte)
cols = ready.RasterXSize
rows = ready.RasterYSize
bands = ready.RasterCount
geotransform = ready.GetGeoTransform()
read_ramdom = ready.ReadAsArray ()

global sum1, sum2, value1, value2
sum1, sum2, value1, value2 = 0, 0, 0, 0
classes = 2
global ssum
def cost(something):

          global ssum
          global sum1, sum2, value1, value2
          global classes
          while classes >=0:
             if something == something:
              something = ready.ReadAsArray()
             elif something == something2:
              something = simul_read.ReadAsArray()

              for i in range (0, rows):
                   for j in range (0, cols):
                      numb =  something [i, j]
                      if numb == 1:
                       one = names [numb -1]
                       ds1 = gdal.Open (one, gdal.GDT_Float32)
                       data1 = ds1.ReadAsArray (j, i, 1, 1)
                       value1 = data1 [0, 0]
                       sum1 = sum1+value1

                      if numb == 2:
                       two = names [numb -1]
                       ds2 = gdal.Open (two, gdal.GDT_Float32)
                       data2 = ds2.ReadAsArray (j, i, 1, 1)
                       value2 = data2 [0, 0]
                       sum2 = sum2+value2
                       classes = classes - 1

          ssum = sum1 + sum2 
          return ssum

simul_read = gdal.Open ('simulated.rst', gdal.GDT_Byte)
read_simulated = simul_read.ReadAsArray ()

A = cost(something) 
B = cost(something2)
C = cost(something) - cost(something2)

print ' The initial COST was :','   ', A, '\n'
print ' The final COST is :','   ', B, '\n'
print ' The gain is :', C , '\n'