make flex and lintsampler optional

Author: michael-petersen

.gitignore

@@ -1,6 +1,8 @@
 *__pycache__/
 *.DS_Store
 
+src/discmodel.egg*
+
 .coverage
 docs/build/
 dist/

README.md

@@ -16,3 +16,22 @@ git clone https://github.com/michael-petersen/discmodel.git
 pip install .
 ```
 
+## Quickstart example
+
+```
+import discmodel
+
+N= 1_000_000
+a = 1.0
+M = 1.0
+rmax = 5.0
+nbins = 100
+mmax,nmax = 2,8
+
+# generate N distributed points
+D = discmodel.DiscGalaxy(N=N, a=a, M=M)
+D.generate_image(rmax=rmax, nbins=nbins)
+
+# now you have
+D.img
+```

pyproject.toml

@@ -8,7 +8,7 @@ requires = [
 build-backend = "setuptools.build_meta"
 
 [project]
-name = "flex"
+name = "discmodel"
 authors = [
   { name="Michael S. Petersen", email="michael.petersen@roe.ac.uk" },
 ]

src/discmodel/__init__.py

@@ -6,6 +6,7 @@
 See README.md for details
 """
 from .discmodel import DiscGalaxy
+from importlib.metadata import version
 
 __version__ = version("discmodel")
 __all__ = ["DiscGalaxy"]

src/discmodel/discmodel.py

@@ -7,12 +7,20 @@
 # for interpolation
 from scipy import interpolate
 
-# for resampling technology
-#from lintsampler import LintSampler
-#import lintsampler
+# check if lintsampler is available
+try:
+    import lintsampler
+    HAS_LINTSAMPLER = True
+except ImportError:
+    HAS_LINTSAMPLER = False
+
+# check if flex is available
+try:
+    import flex
+    HAS_FLEX = True
+except ImportError:
+    HAS_FLEX = False
 
-# if you leave LaguerreAmplitudes in a different file
-from FLEXbase import LaguerreAmplitudes
 
 
 
@@ -205,6 +213,9 @@ def generate_image(self,rmax,nbins,noiselevel=-1.0):
 
     def make_expansion(self,mmax,nmax,rscl,xmax=10000.,noisy=False):
 
+        if not HAS_FLEX:
+            raise ImportError("flex is not available. Please install flex to use this method.")
+
         try:
             snapshot = self.img
         except:
@@ -230,24 +241,29 @@ def make_expansion(self,mmax,nmax,rscl,xmax=10000.,noisy=False):
         #phi[gvals]          = np.nan
         snapshotflat[gvals] = np.nan
 
-        laguerre = LaguerreAmplitudes(rscl,mmax,nmax,rval,phi,snapshotflat)
+        laguerre = flex.FLEX(rscl,mmax,nmax,rval,phi,mass=snapshotflat)
 
         return laguerre
 
     def make_particle_expansion(self,mmax,nmax,rscl,xmax=10000.,noisy=False):
 
-        # no guards here yet, please add one!
+        if not HAS_FLEX:
+            raise ImportError("flex is not available. Please install flex to use this method.")
 
         rval = np.sqrt(self.x**2+self.y**2)
         phi  = np.arctan2(self.y,self.x)
         mass = (self.M/self.N)*np.ones(rval.size)  # this assumes equal weights; the sqrt avoids double counting
 
         # this assumes equal weights
-        laguerre = LaguerreAmplitudes(rscl,mmax,nmax,rval,phi,mass=mass)
+        laguerre = flex.FLEX(rscl,mmax,nmax,rval,phi,mass=mass)
 
         return laguerre
 
     def resample_expansion(self,E):
+
+        if not HAS_LINTSAMPLER:
+            raise ImportError("lintsampler is not available. Please install lintsampler to use this method.")
+        
         def rndmpdf(X): return np.random.uniform()
         g = lintsampler.DensityGrid((self.x_centers,self.x_centers), rndmpdf)
 
@@ -256,7 +272,7 @@ def rndmpdf(X): return np.random.uniform()
 
         g.masses = g._calculate_faverages() * g._calculate_volumes()
         g._total_mass = np.sum(g.masses)
-        pos = LintSampler(g).sample(self.N)
+        pos = lintsampler.LintSampler(g).sample(self.N)
         return pos
 
     def compute_a1(self,E):