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Update coeff-wise quick-reference doc.

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Gael Guennebaud 2015-06-22 14:08:54 +02:00
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@ -364,32 +364,10 @@ vec3 = vec1.cross(vec2);\endcode</td></tr>
<a href="#" class="top">top</a>
\section QuickRef_Coeffwise Coefficient-wise \& Array operators
Coefficient-wise operators for matrices and vectors:
<table class="manual">
<tr><th>Matrix API \matrixworld</th><th>Via Array conversions</th></tr>
<tr><td>\code
mat1.cwiseMin(mat2)
mat1.cwiseMax(mat2)
mat1.cwiseAbs2()
mat1.cwiseAbs()
mat1.cwiseSqrt()
mat1.cwiseProduct(mat2)
mat1.cwiseQuotient(mat2)\endcode
</td><td>\code
mat1.array().min(mat2.array())
mat1.array().max(mat2.array())
mat1.array().abs2()
mat1.array().abs()
mat1.array().sqrt()
mat1.array() * mat2.array()
mat1.array() / mat2.array()
\endcode</td></tr>
</table>
It is also very simple to apply any user defined function \c foo using DenseBase::unaryExpr together with std::ptr_fun:
\code mat1.unaryExpr(std::ptr_fun(foo))\endcode
Array operators:\arrayworld
In addition to the aforementioned operators, Eigen supports numerous coefficient-wise operator and functions.
Most of them unambiguously makes sense in array-world\arrayworld. The following operators are readily available for arrays,
or available through .array() for vectors and matrices:
<table class="manual">
<tr><td>Arithmetic operators</td><td>\code
@ -400,28 +378,107 @@ array1 + scalar array1 - scalar array1 += scalar array1 -= scalar
array1 < array2 array1 > array2 array1 < scalar array1 > scalar
array1 <= array2 array1 >= array2 array1 <= scalar array1 >= scalar
array1 == array2 array1 != array2 array1 == scalar array1 != scalar
array1.min(array2) array1.max(array2) array1.min(scalar) array1.max(scalar)
\endcode</td></tr>
<tr><td>Trigo, power, and \n misc functions \n and the STL variants</td><td>\code
array1.min(array2)
array1.max(array2)
<tr><td>Trigo, power, and \n misc functions \n and the STL-like variants</td><td>\code
array1.abs2()
array1.abs() abs(array1)
array1.sqrt() sqrt(array1)
array1.log() log(array1)
array1.log10() log10(array1)
array1.exp() exp(array1)
array1.pow(exponent) pow(array1,exponent)
array1.pow(array2) pow(array1,array2)
array1.pow(scalar) pow(array1,scalar)
array1.square()
array1.cube()
array1.inverse()
array1.sin() sin(array1)
array1.cos() cos(array1)
array1.tan() tan(array1)
array1.asin() asin(array1)
array1.acos() acos(array1)
array1.atan() atan(array1)
array1.sinh() sinh(array1)
array1.cosh() cosh(array1)
array1.tanh() tanh(array1)
array1.arg() arg(array1)
array1.floor() floor(array1)
array1.ceil() ceil(array1)
array1.round() round(aray1)
array1.isFinite() isfinite(array1)
array1.isInf() isinf(array1)
array1.isNaN() isnan(array1)
\endcode
</td></tr>
</table>
The following coefficient-wise operators are available for all kind of expressions (matrices, vectors, and arrays), and for both real or complex scalar types:
<table class="manual">
<tr><th>Eigen's API</th><th>STL-like APIs\arrayworld </th><th>Comments</th></tr>
<tr><td>\code
mat1.real()
mat1.imag()
mat1.conjugate()
\endcode
</td><td>\code
real(array1)
imag(array1)
conj(array1)
\endcode
</td><td>
\code
// read-write, no-op for real expressions
// read-only for real, read-write for complexes
// no-op for real expressions
\endcode
</td></tr>
</table>
Some coefficient-wise operators are readily available for for matrices and vectors through the following cwise* methods:
<table class="manual">
<tr><th>Matrix API \matrixworld</th><th>Via Array conversions</th></tr>
<tr><td>\code
mat1.cwiseMin(mat2) mat1.cwiseMin(scalar)
mat1.cwiseMax(mat2) mat1.cwiseMax(scalar)
mat1.cwiseAbs2()
mat1.cwiseAbs()
mat1.cwiseSqrt()
mat1.cwiseInverse()
mat1.cwiseProduct(mat2)
mat1.cwiseQuotient(mat2)
mat1.cwiseEqual(mat2) mat1.cwiseEqual(scalar)
mat1.cwiseNotEqual(mat2)
\endcode
</td><td>\code
mat1.array().min(mat2.array()) mat1.array().min(scalar)
mat1.array().max(mat2.array()) mat1.array().max(scalar)
mat1.array().abs2()
mat1.array().abs()
mat1.array().sqrt()
mat1.array().inverse()
mat1.array() * mat2.array()
mat1.array() / mat2.array()
mat1.array() == mat2.array() mat1.array() == scalar
mat1.array() != mat2.array()
\endcode</td></tr>
</table>
The main difference between the two API is that the one based on cwise* methods returns an expression in the matrix world,
while the second one (based on .array()) returns an array expression.
Recall that .array() has no cost, it only changes the available API and interpretation of the data.
It is also very simple to apply any user defined function \c foo using DenseBase::unaryExpr together with <a href="http://en.cppreference.com/w/cpp/utility/functional/ptr_fun">std::ptr_fun</a> (c++03), <a href="http://en.cppreference.com/w/cpp/utility/functional/ref">std::ref</a> (c++11), or <a href="http://en.cppreference.com/w/cpp/language/lambda">lambdas</a> (c++11):
\code
mat1.unaryExpr(std::ptr_fun(foo));
mat1.unaryExpr(std::ref(foo));
mat1.unaryExpr([](double x) { return foo(x); });
\endcode
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\section QuickRef_Reductions Reductions