Merge pull request #200 from matthew-brett/fmri-utils-fixes

matthew-brett · matthew-brett · commit dc1fb39d9a0b · 2012-07-19T17:01:35.000-07:00
RF+TST: Fmri utils fixes

Tests for names for step functions, blocks

Ability to names blocks functions
diff --git a/nipy/modalities/fmri/tests/test_utils.py b/nipy/modalities/fmri/tests/test_utils.py
@@ -3,6 +3,7 @@
 """ Testing fmri utils
 
 """
+import re
 
 import numpy as np
 
@@ -24,7 +25,7 @@
     )
 from .. import hrf
 
-from nose.tools import assert_equal, raises
+from nose.tools import assert_equal, raises, assert_false
 
 from numpy.testing import (assert_array_equal, assert_array_almost_equal,
                            assert_almost_equal)
@@ -99,6 +100,11 @@ def test_step_function():
     s = step_function([0,4,5],[4,2,1])
     lam = lambdify(t, s)
     assert_array_equal(lam(tval), [0, 4, 4, 2, 2, 1])
+    # Name default
+    assert_false(re.match(r'step\d+\(t\)$', str(s)) is None)
+    # Name reloaded
+    s = step_function([0,4,5],[4,2,1], name='goodie_goodie_yum_yum')
+    assert_equal(str(s), 'goodie_goodie_yum_yum(t)')
 
 
 def test_blocks():
@@ -110,6 +116,15 @@ def test_blocks():
     b = blocks(on_off, amplitudes=[3,5])
     lam = lambdify(t, b)
     assert_array_equal(lam(tval), [0, 3, 0, 5])
+    # Check what happens with names
+    # Default is from step function
+    assert_false(re.match(r'step\d+\(t\)$', str(b)) is None)
+    # Can pass in another
+    b = blocks(on_off, name='funky_chicken')
+    assert_equal(str(b), 'funky_chicken(t)')
+
+
+
 
 
 def numerical_convolve(func1, func2, interval, dt, padding_f=0.1):
diff --git a/nipy/modalities/fmri/utils.py b/nipy/modalities/fmri/utils.py
@@ -49,7 +49,7 @@ def lambdify_t(expr):
 
 def define(name, expr):
     """ Create function of t expression from arbitrary expression `expr`
-    
+
     Take an arbitrarily complicated expression `expr` of 't' and make it
     an expression that is a simple function of t, of form ``'%s(t)' %
     name`` such that when it evaluates (via ``lambdify``) it has the
@@ -123,7 +123,7 @@ def interp(times, values, fill=0, name=None, **kw):
     """ Generic interpolation function of t given `times` and `values`
 
     Imterpolator such that:
-    
+
     f(times[i]) = values[i]
 
     if t < times[0]:
@@ -146,7 +146,7 @@ def interp(times, values, fill=0, name=None, **kw):
         Name of symbolic expression to use. If None, a default is used.
     **kw : keyword args, optional
         passed to ``interp1d``
-        
+
     Returns
     -------
     f : sympy expression 
@@ -179,7 +179,7 @@ def linear_interp(times, values, fill=0, name=None, **kw):
     """ Linear interpolation function of t given `times` and `values`
 
     Imterpolator such that:
-    
+
     f(times[i]) = values[i]
 
     if t < times[0]:
@@ -200,10 +200,10 @@ def linear_interp(times, values, fill=0, name=None, **kw):
         Name of symbolic expression to use. If None, a default is used.
     **kw : keyword args, optional
         passed to ``interp1d``
-        
+
     Returns
     -------
-    f : sympy expression 
+    f : sympy expression
         A Function of t.
 
     Examples
@@ -265,7 +265,7 @@ def step_function(times, values, name=None, fill=0):
     if name is None:
         name = 'step%d' % step_function.counter
         step_function.counter += 1
-    
+
     def _imp(x):
         x = np.asarray(x)
         f = np.zeros(x.shape) + fill
@@ -333,7 +333,7 @@ def events(times, amplitudes=None, f=DiracDelta, g=Symbol('a')):
     return e
 
 
-def blocks(intervals, amplitudes=None):
+def blocks(intervals, amplitudes=None, name=None):
     """ Step function based on a sequence of intervals.
 
     Parameters
@@ -343,6 +343,9 @@ def blocks(intervals, amplitudes=None):
        sequences of length 2, giving 'on' and 'off' times of block
     amplitudes : (S,) sequence of float, optional
        Optional amplitudes for each block. Defaults to 1.
+    name : None or str, optional
+       Name of the convolved function in the resulting expression.
+       Defaults to one created by ``utils.interp``.
 
     Returns
     -------
@@ -372,12 +375,12 @@ def blocks(intervals, amplitudes=None):
         v += [a, 0]
     t.append(np.inf)
     v.append(0)
-    return step_function(t, v)
+    return step_function(t, v, name=name)
 
 
 def convolve_functions(fn1, fn2, interval, dt, padding_f=0.1, name=None):
     """ Expression containing numerical convolution of `fn1` with `fn2`
-    
+
     Parameters
     ----------
     fn1 : sympy expr
