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<head><title>Matrix _ List -- select columns</title>
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<div><h1>Matrix _ List -- select columns</h1>
<div class="single"><h2>Synopsis</h2>
<ul><li><div class="list"><dl class="element"><dt class="heading">Usage: </dt><dd class="value"><div><tt>f_cols</tt></div>
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<li><span>Operator: <a href="__us.html" title="a binary operator, used for subscripting and access to elements">_</a></span></li>
<li><div class="single">Inputs:<ul><li><span><tt>f</tt>, <span>a <a href="___Matrix.html">matrix</a></span>, a matrix between free modules</span></li>
<li><span><tt>cols</tt>, <span>a <a href="___List.html">list</a></span>, a list of integers denoting the choice of columns</span></li>
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<li><div class="single">Outputs:<ul><li><span><span>a <a href="___Matrix.html">matrix</a></span>, the submatrix of <tt>f</tt> corresponding to the columns <tt>cols</tt>.</span></li>
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<div class="single"><h2>Description</h2>
<div>This is the same as calling <a href="_submatrix_lp__Matrix_cm__Visible__List_rp.html">submatrix(f,cols)</a>.<table class="examples"><tr><td><pre>i1 : R = QQ[a..f];</pre>
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<tr><td><pre>i2 : p = matrix {{a,b,c},{d,e,f}}
o2 = | a b c |
| d e f |
2 3
o2 : Matrix R <--- R</pre>
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<tr><td><pre>i3 : p_{1}
o3 = | b |
| e |
2 1
o3 : Matrix R <--- R</pre>
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<tr><td><pre>i4 : p_{1,2,0}
o4 = | b c a |
| e f d |
2 3
o4 : Matrix R <--- R</pre>
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<div class="single"><h2>See also</h2>
<ul><li><span><a href="_submatrix.html" title="">submatrix</a></span></li>
<li><span><a href="___Matrix_sp^_sp__List.html" title="select rows">Matrix ^ List</a> -- select rows</span></li>
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