Python: float()参数必须是字符串或数字，而不是'interp2d'

this code returns the error "float() argument must be a string or a number, not 'interp2d'". I'm attempting to learn how to interpolate values to fill an array given a few of the values in the array (sorry, bad phrasing). Am I messing up the syntax for the interp2d function or what?

此代码返回错误“float()参数必须是字符串或数字，而不是'interp2d'”。我正在尝试学习如何在给定数组中的一些值的情况下插入值来填充数组(不好意思，措辞不好)。我是不是把interp2d的语法搞乱了?

import numpy as np
import matplotlib.pyplot as plt
from netCDF4 import Dataset
import scipy as sp

GCM_file = '/Users/Robert/Documents/Python Scripts/GCMfiles/ATM_echc0003_1979_2008.nc'
fh = Dataset(GCM_file, mode = 'r')

pressure = fh.variables['lev'][:]
lats = fh.variables['lat'][:]
temp = np.mean(fh.variables['t'][0,:,:,:,:], axis = (0, 3))
potential_temp = np.zeros((np.size(temp,axis=0), np.size(temp,axis=1)))

P0 = pressure[0] 
#plt.figure(0)
for j in range(0, 96):
    potential_temp[:,j] = temp[:, j] * (P0/ pressure[:]) ** .238


potential_temp_view = potential_temp.view()

temp_view = temp.view()

combo_t_and_pt = np.dstack((potential_temp_view,temp_view))
combo_view = combo_t_and_pt.view()

pt_and_t_flat=np.reshape(combo_view, (26*96,2))
t_flat = temp.flatten()
pt_flat = potential_temp.flatten()

temp_grid = np.zeros((2496,96))

for j in range(0, 2496):
    if j <= 95:
        temp_grid[j,j] = t_flat[j]
    else:
            temp_grid[j, j % 96] = t_flat[j]

'''Now you have the un-interpolated grid of all your values of t as a function of potential temp and latitude, so you have to interpolate the rest somehow....?'''

xlist = lats
ylist = pt_flat

X,Y = np.meshgrid(xlist,ylist)



temp_cubic = sp.interpolate.interp2d(xlist,ylist, temp_grid, kind = 'cubic')
#temp_linear= griddata(temp_grid, (X,Y), method = 'linear')
#temp_quintic = griddata(temp_grid, (X,Y), method = 'cubic')

plt.figure(0)
plt.contourf(X,Y, temp_cubic, 20)

EDIT: The error with this was pointed out to me. I changed the code from the interpolating line down into this, and I'm still getting an error, which reads "ValueError: Invalid input data". Here's the traceback:

编辑:我发现了这个错误。我将代码从插值行修改为这个，我仍然得到一个错误，它是“ValueError:无效输入数据”。回溯:

runfile('C:/Users/Robert/Documents/Python Scripts/attempt at defining potential temperature.py', wdir='C:/Users/Robert/Documents/Python Scripts')
Traceback (most recent call last):
  File "<ipython-input-27-1ffd3fcc3aa1>", line 1, in <module>
    runfile('C:/Users/Robert/Documents/Python Scripts/attempt at defining potential temperature.py', wdir='C:/Users/Robert/Documents/Python Scripts')
  File "C:\Users\Robert\Anaconda3\lib\site-packages\spyderlib\widgets\externalshell\sitecustomize.py", line 699, in runfile
    execfile(filename, namespace)
  File "C:\Users\Robert\Anaconda3\lib\site-packages\spyderlib\widgets\externalshell\sitecustomize.py", line 88, in execfile
    exec(compile(open(filename, 'rb').read(), filename, 'exec'), namespace)
  File "C:/Users/Robert/Documents/Python Scripts/attempt at defining potential temperature.py", line 62, in <module>
    Z = temp_cubic(xlist,ylist)
  File "C:\Users\Robert\Anaconda3\lib\site-packages\scipy\interpolate\interpolate.py", line 292, in __call__
    z = fitpack.bisplev(x, y, self.tck, dx, dy)
  File "C:\Users\Robert\Anaconda3\lib\site-packages\scipy\interpolate\fitpack.py", line 1048, in bisplev
    raise ValueError("Invalid input data")":

temp_cubic = sp.interpolate.interp2d(xlist, ylist, temp_grid, kind = 'cubic')

ylist = np.linspace(np.min(pt_flat), np.max(pt_flat), .01)

X,Y = np.meshgrid(xlist,ylist)
Z = temp_cubic(xlist,ylist)
plt.contourf(X,Y, Z, 20)

1 个解决方案

#1

The problem is in the following line. interp2d returns an interpolation function. However, you used it in place of the Z argument to countourf, which is supposed to be a float matrix. See the contourf doc for details.

问题在下面。interp2d返回一个插值函数。但是，你用它来代替Z参数countourf，它应该是一个浮点矩阵。详情请参阅contourf doc。

In particular:

特别是:

contour(X,Y,Z,N)
make a contour plot of an array Z.
X, Y specify the (x, y) coordinates of the surface
X and Y must both be 2-D with the same shape as Z,
  or they must both be 1-D such that
  len(X) is the number of columns in Z and
  len(Y) is the number of rows in Z.
contour up to N automatically-chosen levels.

In short, I believe that you want to apply the function to X and Y to generate the array you pass in as the third argument.

简而言之，我认为您希望将函数应用于X和Y，以生成作为第三个参数传入的数组。

Credit to both the matplotlib documentation and kindall for showing the conceptual error of my other possibilities.

感谢matplotlib文档和kindall显示了其他可能性的概念错误。

#1