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annotate toolbox/chop.m @ 2:c124219d7bfa draft

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Re-add the 1995 toolbox after noticing the statement in the ~higham/mctoolbox/ webpage.
author Antonio Pino Robles <data.script93@gmail.com>
date Thu, 07 May 2015 18:36:24 +0200
parents 8f23314345f4
children
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8f23314345f4 Create local repository for matrix toolboxes. Step #0 done.
Antonio Pino Robles <data.script93@gmail.com>
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1 function c = chop(x, t)
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2 %CHOP Round matrix elements.
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3 % CHOP(X, t) is the matrix obtained by rounding the elements of X
8f23314345f4 Create local repository for matrix toolboxes. Step #0 done.
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4 % to t significant binary places.
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5 % Default is t = 24, corresponding to IEEE single precision.
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7 if nargin < 2, t = 24; end
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8 [m, n] = size(x);
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8f23314345f4 Create local repository for matrix toolboxes. Step #0 done.
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10 % Use the representation:
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11 % x(i,j) = 2^e(i,j) * .d(1)d(2)...d(s) * sign(x(i,j))
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13 % On the next line `+(x==0)' avoids passing a zero argument to LOG, which
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14 % would cause a warning message to be generated.
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16 y = abs(x) + (x==0);
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17 e = floor(log2(y) + 1);
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18 c = pow2(round( pow2(x, t-e) ), e-t);