Some updates to README and setup

README.md

@@ -15,11 +15,20 @@ usage.
 
 ## Required packages
 
-These packages might be needed:
+These `python` packages are needed:
 * `scikit-sparse`
 * `numpy`
 * `scipy`
 
+For installing [`scikit-sparse`](https://github.com/scikit-sparse/scikit-sparse),
+the library `suite-sparse` is required.
+As also highlighted [here](https://github.com/scikit-sparse/scikit-sparse),
+there may appear problems installing `scikit-sparse` on a Mac,
+which is due to the `suite-sparse` location not being installed at the right place.
+For fixing this, just find out your `lib` and `include` directory of your `suite-sparse`
+and use the respective `pip install` command which defines
+`SUITESPARSE_INCLUDE_DIR` and `SUITESPARSE_LIBRARY_DIR` manually.
+
 ## Getting started
 You can find some examples on how to use it in the test directory
 `test`. See e.g. the example in `gridlod/test/test_pgexamples.py`. The
@@ -85,4 +94,4 @@ illustrative. Use e.g. `nosetests` to run the tests.
 ## Contributors
 
 * Fredrik Hellman
-* Tim Keil
+* Tim Keil

gridlod/func.py

@@ -56,7 +56,7 @@ def evaluateCQ1(N, cq1, coordinates):
     interpolationWeights = np.zeros((coordinates.shape[0], 2**d))
     for localNode in range(2**d):
         localNodeBinaryString = bin(localNode)[2:].zfill(d)[::-1]
-        localNodeBitmap = np.array([0 if bit is '0' else 1 for bit in localNodeBinaryString])
+        localNodeBitmap = np.array([0 if bit == '0' else 1 for bit in localNodeBinaryString])
 
         # This computes the value of the basis function at node
         # localNode for all points. It is a product of either x_k or
@@ -97,7 +97,7 @@ def evaluateCQ1D(N, cq1, coordinates):
     interpolationWeights = np.zeros((coordinates.shape[0], 2**d, d))
     for localNode in range(2**d):
         localNodeBinaryString = bin(localNode)[2:].zfill(d)[::-1]
-        localNodeBitmap = np.array([0 if bit is '0' else 1 for bit in localNodeBinaryString])
+        localNodeBitmap = np.array([0 if bit == '0' else 1 for bit in localNodeBinaryString])
         for dimensionToDifferentiate in range(d):
             # These are the factors x_k or (1-x_k)
             interpolationWeightsFactors = (1.0 - localNodeBitmap) + (2.0*localNodeBitmap - 1.0)*coordIndicesFpart

requirements.txt

@@ -0,0 +1,3 @@
+numpy==1.23.4
+scikit-sparse==0.4.7
+scipy==1.9.3