Webapp (#4)

* Add web app using pyodide, preact+htm and plotly

Only Resolution, Flux-Ei and Flux-Freq plots so far
Need Instruments.py modifications to work in javascript
  (explicit conversion to/from np.array and sets as
   pyodide does not handle these types well in proxy)
Currently set up to use local js files rather than CDN

* Add QE and time-distance plots

Change to use plotly and pyodide from CDN
Modify Instruments.py to output lines in plotMultiRepFrame
  if cannot import matplotlib
Modify Instruments.py to respect type of phase (str / number)
  In Javascript, always assume it is a number...

* Update gh-actions and readme

* Modify MulpyRep to sim t-d graphs for single chopper inst

* Update tests

Author: mducle

.github/workflows/tests.yaml

@@ -2,15 +2,23 @@ name: Run test and coverage
 
 on:
     push:
+      branches: [main]
     pull_request:
+      branches: [main]
+      types: [opened, reopened, synchronize]
+    release:
+      types: [published]
+    workflow_dispatch:
 
 jobs:
   build:
     runs-on: ubuntu-latest
 
     steps:
     - name: Checkout
-      uses: actions/checkout@v2
+      uses: actions/checkout@v3
+      with:
+        fetch-depth: 0
 
     - name: Run tests
       run: |
@@ -23,3 +31,30 @@ jobs:
       uses: codecov/codecov-action@v2
       with:
         fail_ci_if_error: true
+
+    - name: Upload webapp
+      if: ${{ github.event_name == 'release' || github.event_name == 'push' || github.event_name == 'workflow_dispatch' }}
+      run: |
+        cp -rpa webapp webtmp
+        tar zcf webtmp/pychop.tar.gz --exclude __main__.py --exclude PyChopGui.py --exclude __pycache__ PyChop/
+        git checkout --force gh-pages
+        git config --global user.email "[email protected]"
+        git config --global user.name "Github Actions"
+        if [[ "${{ github.event_name }}" == "pull_request" ]]; then
+          git rm -rf $GITHUB_REF || true
+          rm -rf $GITHUB_REF
+          mv webtmp $GITHUB_REF
+          git add $GITHUB_REF
+          git commit --allow-empty -m "Update web-app files for release $GITHUB_REF"
+        else
+          git rm -rf unstable/* || true
+          mv webtmp/* unstable/*
+          git add unstable
+          git commit --allow-empty -m "Update web-app files for update $GITHUB_SHA"
+        fi
+        remote_repo="https://${GITHUB_ACTOR}:${{ secrets.GITHUB_TOKEN }}@github.com/mducle/pychop.git"
+        git push ${remote_repo} HEAD:gh-pages --follow-tags
+
+    - name: Setup tmate session
+      if: ${{ failure() }}
+      uses: mxschmitt/action-tmate@v3

PyChop/Instruments.py

@@ -85,6 +85,17 @@ def soft_hat(x, p):
     return y
 
 
+class PltDummy(object):
+    # Class to act as a dummy saving all "plot" and "text" commands to a list
+    def __init__(self):
+        self.history = []
+    def __getattr__(self, name):
+        def passthrough(*args, **kwargs):
+            if name == 'plot' or name == 'text':
+                self.history.append([name, args, kwargs])
+        return passthrough
+
+
 class FermiChopper(object):
     """
     Class which represents a Fermi chopper package
@@ -159,6 +170,7 @@ def __init__(self, inval=None):
         self._parse_variants()
         self.phase = self.defaultPhase
         self.frequency = self.default_frequencies
+        self.not_warn = True
 
     def __repr__(self):
         return self.name if self.name else "Undefined disk chopper system"
@@ -273,7 +285,8 @@ def setFrequency(self, *args, **kwargs):
         if argdict["freq"]:
             self.frequency = argdict["freq"]
         if argdict["phase"]:
-            self.phase = argdict["phase"]
+            self.phase = [str(p) if isinstance(self.defaultPhase[i], str) else float(p)
+                          for i, p in enumerate(argdict["phase"])]
 
     def getFrequency(self):
         return self.frequency
@@ -290,7 +303,7 @@ def getEi(self):
         return self.ei
 
     def getAllowedEi(self, Ei_in=None):
-        return set(np.round(self._MulpyRepDriver(Ei_in, calc_res=False)[0], decimals=4))
+        return list(set(np.round(self._MulpyRepDriver(Ei_in, calc_res=False)[0], decimals=4)))
 
     def plotMultiRepFrame(self, h_plt=None, Ei_in=None, frequency=None, first_rep=False):
         """
@@ -301,8 +314,12 @@ def plotMultiRepFrame(self, h_plt=None, Ei_in=None, frequency=None, first_rep=Fa
             try:
                 from matplotlib import pyplot
             except ImportError:
-                raise RuntimeError("plotMultiRepFrame: Cannot import matplotlib")
-            plt = pyplot
+                if self.not_warn:
+                    warnings.warn("plotMultiRepFrame: Cannot import matplotlib, will return list of lines")
+                    self.not_warn = False
+                plt = PltDummy()
+            else:
+                plt = pyplot
         else:
             plt = h_plt
         _check_input(self, Ei_in)
@@ -354,6 +371,8 @@ def plotMultiRepFrame(self, h_plt=None, Ei_in=None, frequency=None, first_rep=Fa
             plt.set_xlim(0, xmax)
             plt.set_xlabel(r"TOF ($\mu$sec)")
             plt.set_ylabel(r"Distance (m)")
+        if isinstance(plt, PltDummy):
+            return plt.history
 
     def getWidthSquared(self, Ei_in=None):
         return self.getWidth(Ei_in, squared=True)
@@ -604,28 +623,25 @@ def getAnalyticWidthsSquared(self, Ei):
 
     def getWidthSquared(self, Ei):
         """Returns the squared time gaussian FWHM width due to the sample in s^2"""
-        if hasattr(self, "width_interp"):
-            wavelength = np.sqrt(E2L / (Ei if not hasattr(Ei, "__len__") else Ei[0]))
-            if wavelength >= self.wmn:
-                # Data is obtained from measuring widths of powder Bragg peaks in backscattering
-                # At low wavelengths / high energies, the peaks are too close together to discern
-                # so there is no measurements, but the analytical expressions should still be good.
-                width = self.width_interp(min([wavelength, self.wmx])) ** 2 / 1e12
-                return (width * SIGMA2FWHMSQ) if self.measured_width["isSigma"] else width
+        if hasattr(self, "width_interp") or self.imod == 3:
+            return self.getWidth(Ei) ** 2
         return self.getAnalyticWidthsSquared(Ei)
 
     def getWidth(self, Ei):
         """Calculates the moderator time width in seconds for a given neutron energy (Ei)"""
         if hasattr(self, "width_interp"):
             wavelength = np.sqrt(E2L / (Ei if not hasattr(Ei, "__len__") else Ei[0]))
             if wavelength >= self.wmn:
+                # Data is obtained from measuring widths of powder Bragg peaks in backscattering
+                # At low wavelengths / high energies, the peaks are too close together to discern
+                # so there is no measurements, but the analytical expressions should still be good.
                 width = self.width_interp(min([wavelength, self.wmx])) / 1e6  # Table has widths in microseconds
                 return width * SIGMA2FWHM if self.measured_width["isSigma"] else width
         if self.imod == 3:
             # Mode for LET - output of polynomial is FWHM in us
             return np.polyval(self.mod_pars, np.sqrt(E2L / Ei)) / 1e6
         else:
-            return np.sqrt(self.getAnalyticWidthSquared(Ei))
+            return np.sqrt(self.getAnalyticWidthsSquared(Ei))
 
     def getFlux(self, Ei):
         """Returns the white beam flux estimate from either measured data (preferred) or analytical model (backup)"""
@@ -854,7 +870,7 @@ def getMultiRepResolution(self, Etrans=None, Ei_in=None, frequency=None):
         Ei = _check_input(self.chopper_system, Ei_in)
         if Etrans is None:
             Etrans = np.linspace(0.05, 0.95, 19, endpoint=True)
-        return [self.getResolution(Etrans * ei, ei, frequency) for ei in self.getAllowedEi(Ei)]
+        return [self.getResolution(np.array(Etrans) * ei, ei, frequency) for ei in self.getAllowedEi(Ei)]
 
     def getVanVar(self, Ei_in=None, frequency=None, Etrans=0):
         """Calculates the time squared FWHM in s^2 at the sample (Vanadium widths) for different components"""

PyChop/MulpyRep.py

@@ -194,6 +194,15 @@ def calcChopTimes(efocus, freq, instrumentpars, chop2Phase=5):
     uSec = 1e6  # seconds to microseconds
     lam = np.sqrt(81.8042 / efocus)  # convert from energy to wavelenth
 
+    # if there's only one disk we prepend a dummy disk with full opening at zero distance
+    # so that the distance calculations (which needs the difference between disk pos) works
+    if len(instrumentpars[0]) == 1:
+        for d1, i in zip([[0], [1], None, [3141], [10], [500], [1]], range(7)):
+            instrumentpars[i] = (d1 + instrumentpars[i]) if d1 is not None else [d1, instrumentpars[i]]
+        prepend_disk = True
+    else:
+        prepend_disk = False
+
     # extracts the instrument parameters
     dist, nslot, slots_ang_pos, slot_width, guide_width, radius, numDisk = tuple(instrumentpars[:7])
     samp_det, chop_samp, rep, tmod, frac_ei, ph_ind_v = tuple(instrumentpars[7:])
@@ -219,6 +228,9 @@ def calcChopTimes(efocus, freq, instrumentpars, chop2Phase=5):
     source_rep, nframe = tuple(rep[:2]) if (hasattr(rep, "__len__") and len(rep) > 1) else (rep, 1)
     p_frames = source_rep / nframe
 
+    if prepend_disk:
+        freq = np.array([source_rep, freq[0]])
+
     # first we optimise on the main Ei
     for i in range(len(dist)):
         # loop over each chopper

README.md

@@ -1,15 +1,17 @@
 # PyChop Stand-alone
 
 PyChop is a program to calculate the energy resolution of a time-of-flight (ToF) neutron spectrometer
-from the burst time of the instruments moderator and the opening times of its choppers.
+from the burst time of the instrument's moderator and the opening times of its choppers.
 
 The code is based on `CHOP`, a fortran program written by T. G. Perring,
 and `multirep`, a Matlab program by R. I. Bewley.
 
-This is a port of the [Mantid PyChop](https://github.com/mantidproject/mantid/tree/master/scripts/PyChop) code to work without Mantid.
+This is a port of the [Mantid PyChop](https://github.com/mantidproject/mantid/tree/master/scripts/PyChop)
+code to work without Mantid.
 
 Further documentation is available on the [Mantid webpage](https://docs.mantidproject.org/nightly/interfaces/PyChop.html)
 
+A web version is accessible at [https://mducle.github.io/pychop/unstable/](https://mducle.github.io/pychop/unstable/)
 
 ## Installation
 Optionally create and activate a `venv` virtual environment to isolate `PyChop` from your system packages
@@ -28,4 +30,4 @@ this installation method should ensure that all requisite dependencies are avail
 Launch the `PyChop` GUI via the installed project script
 ```shell
 PyChop
-```
+```

tests/PyChopTest.py

@@ -13,18 +13,21 @@
 import warnings
 import numpy as np
 
-from PyChop import PyChop2
-
 
 class PyChop2Tests(unittest.TestCase):
 
+    @classmethod
+    def setUpClass(cls):
+        from PyChop import PyChop2
+        cls.PyChop2 = PyChop2
+
     # Tests the Fermi chopper instruments
     def test_pychop_fermi(self):
         instnames = ['maps', 'mari', 'merlin']
         res = []
         flux = []
         for inc, instname in enumerate(instnames):
-            chopobj = PyChop2(instname)
+            chopobj = self.PyChop2(instname)
             # Code should give an error if the chopper settings and Ei have
             # not been set.
             self.assertRaises(ValueError, chopobj.getResolution)
@@ -44,7 +47,7 @@ def test_pychop_fermi(self):
         self.assertLess(res[1][0], res[2][0])
         # Now tests the standalone function
         for inc, instname in enumerate(instnames):
-            rr, ff = PyChop2.calculate(instname, 's', 200, 18, 0)
+            rr, ff = self.PyChop2.calculate(instname, 's', 200, 18, 0)
             self.assertAlmostEqual(rr[0], res[inc][0], places=7)
             self.assertAlmostEqual(ff, flux[inc], places=7)
 
@@ -54,7 +57,7 @@ def test_pychop_let(self):
         res = []
         flux = []
         for inc, variant in enumerate(variants):
-            chopobj = PyChop2('LET', variant)
+            chopobj = self.PyChop2('LET', variant)
             # Checks that it instantiates the correct variant
             self.assertTrue(variant in chopobj.getChopper())
             # Code should give an error if the chopper settings and Ei have
@@ -73,12 +76,12 @@ def test_pychop_let(self):
         self.assertLessEqual(res[1][0], res[0][0])
         # Now tests the standalone function
         for inc, variant in enumerate(variants):
-            rr, ff = PyChop2.calculate('LET', variant, 200, 18, 0)
+            rr, ff = self.PyChop2.calculate('LET', variant, 200, 18, 0)
             self.assertAlmostEqual(rr[0], res[inc][0], places=7)
             self.assertAlmostEqual(ff, flux[inc], places=7)
 
     def test_pychop_invalid_ei(self):
-        chopobj = PyChop2('MARI', 'G', 400.)
+        chopobj = self.PyChop2('MARI', 'G', 400.)
         chopobj.setEi(120)
         with warnings.catch_warnings(record=True) as w:
             res = chopobj.getResolution(130.)
@@ -98,10 +101,14 @@ def test_pychop_numerics(self):
         ref_flux = [2055.562054927915, 128986.24972543867, 0.014779264739956933, 45438.33797146135,
                     24196.496233770937, 5747.118187298609, 22287.647098883135, 4063.3113893387676]
         for inst, ch, frq, ei, res0, flux0 in zip(instruments, choppers, freqs, eis, ref_res, ref_flux):
-            res, flux = PyChop2.calculate(inst, ch, frq, ei, 0)
+            res, flux = self.PyChop2.calculate(inst, ch, frq, ei, 0)
             np.testing.assert_allclose(res[0], res0, rtol=1e-7, atol=0)
             np.testing.assert_allclose(flux[0], flux0, rtol=1e-7, atol=0)
 
+    #def test_pychop_imports(self):
+    #    # Tests we can run without scipy and matplotlib (not used for webapp)
+
+
 
 class MockedModule(mock.MagicMock):
     # A class which is meant to act like a module
@@ -388,5 +395,49 @@ def test_merlin_specials(self):
         self.window.widgets['Chopper0Phase']['Edit'].show.assert_called()
 
 
+class PyChopImportTests(unittest.TestCase):
+    # Tests we can run without scipy and matplotlib (not used for webapp)
+
+    def test_no_scipy(self):
+        # Tests that without scipy, the answers are _almost_ the same
+        ref_vals = [0.08079912729715726, 45438.33797146135] # Calculated with scipy
+        real_import = builtins.__import__
+        def my_import_func(name, globals=None, locals=None, fromlist=(), level=0):
+            if 'scipy' in name:
+                raise ModuleNotFoundError
+            else:
+                return real_import(name, globals, locals, fromlist, level)
+        # Now remove reference to scipy.interpolate if it's already been imported
+        import sys
+        savemods = {}
+        for mod in ['scipy.interpolate'] + [m for m in sys.modules if m.startswith('PyChop')]:
+            if mod in sys.modules:
+                savemods[mod] = sys.modules[mod]
+                del sys.modules[mod]
+        with patch('builtins.__import__', my_import_func):
+            from PyChop import PyChop2
+            res, flux = PyChop2.calculate('LET', 'High Flux', [240, 120], 3.7, 0)
+            # Resolution does not require interpolation
+            np.testing.assert_allclose(res, ref_vals[0], rtol=1e-7, atol=0)
+            np.testing.assert_allclose(flux, ref_vals[1], rtol=1e-2, atol=0)
+        for modname, mod in savemods.items():
+            sys.modules[modname] = mod
+
+    def test_no_maptlotlib(self):
+        # Tests that without matplotlib, plotMultiRepFrame returns a list of lines
+        real_import = builtins.__import__
+        def my_import_func(name, globals=None, locals=None, fromlist=(), level=0):
+            if 'matplotlib' in name:
+                raise ModuleNotFoundError
+            else:
+                return real_import(name, globals, locals, fromlist, level)
+        with patch('builtins.__import__', my_import_func):
+            from PyChop import PyChop2
+            pcobj = PyChop2('ARCS', 'ARCS-100-1.5-AST', 300)
+            with self.assertWarns(Warning):
+                rv = pcobj.chopper_system.plotMultiRepFrame(Ei_in=120)
+                self.assertTrue(rv is not None and len(rv) > 0)
+
+
 if __name__ == "__main__":
     unittest.main()

webapp/README.md

@@ -0,0 +1,31 @@
+# PyChop Webapp
+
+The PyChop webapp is a single-page application running directly in the browser.
+You can edit the javascript and html code directly to change the app behaviour,
+but as a convenience it is nicer to use [browser-sync](https://browsersync.io/)
+to automatically reload when any of the code changes.
+
+Create a file `package.json` in this folder with this content:
+
+```javascript
+{
+  "scripts": {
+    "start": "browser-sync start --server . --files . --single"
+  },
+}
+```
+
+and run
+
+```shell
+npm start
+```
+
+(You need to install [node.js](https://nodejs.org/en)).
+
+We use [preact.js](https://preactjs.com/)+[htm](https://github.com/developit/htm) to define the UI,
+[pyodide](https://pyodide.org) to run the Python code to do the actual calculations and
+[plotly](https://plotly.com/javascript/) for the graphs.
+These dependencies are downloaded from content delivery networks, which takes a few seconds depending
+on your connection speed and which are then cached.
+You can also download the `.js` files imported in `pychop.js` directly for faster processing.