SamplePublisher`GrassmannCalculus`DifferentialGeometry`
ExpandAndEvaluateDirectionalDerivatives  |
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Details and Options
Examples
(1)
Basic Examples
(1)
In[1]:=
<<GrassmannCalculus`
In[2]:=
savePreferences=
;
 | AllPreferences |
Work in the GrassmannPlane.
In[3]:=
SetPreferences["GrassmannPlane","Vector"]
The following will not evaluate because the direction has not been expanded to basis vectors.
In[4]:=
∇
e
x
e
y
2
y
 | EvaluateDirectionalDerivatives |
Out[4]=
∇
e
x
e
y
2
y
Out[4]=
∇
e
x
e
y
2
y
The following expands first and then evaluates a directional derivative.
In[5]:=
∇
e
x
e
y
2
y
| ExpandDirectionalDerivatives |
| EvaluateDirectionalDerivatives |
Out[5]=
∇
e
x
e
y
2
y
Out[5]=
3[](x+Cos[xy])+4[](x+Cos[xy])
∇
e
x
2
y
∇
e
y
2
y
Out[5]=
4(2xy-xSin[xy])+3(-ySin[xy])
2
y
It could be done in one step with:
In[6]:=
∇
e
x
e
y
2
y
| ExpandAndEvaluateDirectionalDerivatives |
Out[6]=
∇
e
x
e
y
2
y
Out[6]=
4(2xy-xSin[xy])+3(-ySin[xy])
2
y
In[7]:=
| RestorePreferences |
""