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.\" RCSid "$Id$" |
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.TH RMTXOP 1 7/8/97 RADIANCE |
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.SH NAME |
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rmtxop - concatenate, add, transpose, scale, and convert matrices |
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rmtxop - concatenate, add, multiply, divide, transpose, scale, and convert matrices |
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.SH SYNOPSIS |
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.B rmtxop |
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[ |
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.B "\-s sf .." |
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][ |
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.B "\-c ce .." |
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][ |
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.B -r[fb] |
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] |
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.B m1 |
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[ |
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.B + |
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.B ".+*/" |
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] |
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.B ".." |
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.SH DESCRIPTION |
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.I Rmtxop |
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loads and concatenates (multiplies) or adds together component matrix files |
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given on the command line. |
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loads and concatenates or adds/multiplies/divides |
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together component matrix files given on the command line. |
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Each file must have a header containing the following variables: |
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.sp |
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.nf |
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A matrix may be read from the standard input using a hyphen by itself ('-') |
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in the appropriate place on the command line. |
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.PP |
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Any of the matrix inputs may be read from a command |
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instead of a file by |
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using quotes and a beginning exclamation point ('!'). |
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.PP |
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Two special cases are handled for component matrices that are either |
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XML files containing BTDF data, or Radiance picture files. |
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In the first case, a BSDF library is used to load and interpret the |
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transmission matrix. |
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(XML files cannot be read from the standard input.)\0 |
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XML files containing BSDF data, or Radiance picture files. |
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In the first case, the BSDF library loads and interprets the |
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transmission matrix by default. |
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Alternatively, the front (normal-side) reflectance is selected if the |
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.I \-rf |
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option precedes the file name, or the backside reflectance if |
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.I \-rb |
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is specified. |
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(XML files cannot be read from the standard input or from a command.)\0 |
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In the second case, the RGBE or XYZE values are loaded in a 3-component |
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matrix where the number of columns match the X-dimension of the picture, and |
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the number of rows match the Y-dimension. |
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The picture must be in standard pixel ordering, and the first row |
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is at the top with the first column on the left. |
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Any exposure changes applied to the pictures beforehand |
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.I rmtxop |
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will be undone, similar to the |
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.I pcomb(1) |
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.I \-o |
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option. |
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.PP |
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Before each file, the |
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.I \-t |
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to the same input matrix. |
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.PP |
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If present, the second and subsequent matrices on the command |
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line are concatenated to the result unless separated by a plus ('+') symbol, |
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in which case the elements are added together. |
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The number of components in the new matrix after applying any |
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line are concatenated together, unless separated by a plus ('+'), |
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asterisk ('*'), or forward slash ('/') symbol, |
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in which case the individual matrix elements are added, |
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multiplied, or divided, respectively. |
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The concatenation operator ('.') is the default and need not be specified. |
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Note also that the asterisk must be quoted or escaped in most shells. |
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In the case of addition, the two matrices involved must have the same number |
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of components. |
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If subtraction is desired, use addition ('+') with a scaling parameter of -1 |
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for the second matrix (the |
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.I \-s |
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option). |
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For element-wise multiplication and division, the second matrix is |
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permitted to have a single component per element, which will be |
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applied equally to all components of the first matrix. |
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If element-wise division is specified, any zero elements in the second |
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matrix will result in a warning and the corresponding component(s) in the |
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first matrix will be set to zero. |
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.PP |
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Evaluation proceeds from left to right, and all operations have |
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the same precedence. |
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If a different evaluation order is desired, pipe the result of one |
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.I rmtxop |
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command into another, as shown in one of the examples below. |
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.PP |
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The number of components in the next matrix after applying any |
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.I -c |
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transform must agree with the prior result. |
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For concatenation (matrix multiplication), the number of columns |
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in the prior result must equal the number of rows in the new matrix, and |
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in the prior result must equal the number of rows in the next matrix, and |
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the result will have the number of rows of the previous and the number |
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of columns of the new matrix. |
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In the case of addition, the number of rows and columns of the prior |
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result and the new matrix must match, and will not be changed by the |
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operation. |
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of columns of the next matrix. |
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In the case of addition, multiplication, and division, |
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the number of rows and columns of the prior result and the |
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next matrix must match, and will not be changed by the operation. |
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.PP |
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A final transpose or scaling/transform operation may be applied to |
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the results by appending the |
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.I \-t |
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and |
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.I \-s |
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or |
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.I \-c |
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options after the last matrix on the command line. |
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.PP |
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Results are sent to the standard output. |
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By default, the values will be written in the lowest resolution format |
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among the inputs, but the |
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.IP "" .2i |
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rmtxop -fc blinds.xml > blinds.hdr |
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.PP |
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To extract the luminance values from a picture as an ASCII matrix: |
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.IP "" .2i |
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rmtxop -fa -c .265 .670 .065 image.hdr > image_lum.mtx |
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.PP |
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To scale a matrix by 4 and add it to the transpose of another matrix: |
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.IP "" .2i |
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rmtxop -s 4 left.mtx + -t right.mtx > result.mtx |
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rmtxop -s 4 first.mtx + -t second.mtx > result.mtx |
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.PP |
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To multiply elements of two matrices, then concatenate with a third, |
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applying a final transpose to the result: |
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.IP "" .2i |
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rmtxop first.mtx \\* second.mtx . third.mtx -t > result.mtx |
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.PP |
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To left-multiply the element-wise division of two matrices: |
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.IP "" .2i |
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rmtxop -fd numerator.mtx / denominator.mtx | rmtxop left.mtx - > result.mtx |
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.PP |
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To send the elements of a binary matrix to |
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.I rcalc(1) |
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for further processing: |
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.IP "" .2i |
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rmtxop -fa orig.mtx | rcollate -ho -oc 1 | rcalc [operations] |
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.SH NOTES |
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Matrix concatenation is associative but not commutative, so order |
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matters to the result. |
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.I Rmtxop |
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takes advantage of this associative property to concatenate |
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from right to left when it reduces the number of basic operations. |
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If the rightmost matrix is a column vector for example, it is |
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much faster to concatenate from the right, and the result will |
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be the same. |
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Note that this only applies to concatenation; |
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element-wise addition, multiplication, and division are always |
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evaluated from left to right. |
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.SH AUTHOR |
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Greg Ward |
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.SH "SEE ALSO" |
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cnt(1), getinfo(1), histo(1), neaten(1), rcalc(1), rcollate(1), |
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rcontrib(1), rfluxmtx(1), rlam(1), tabfunc(1), total(1) |
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cnt(1), getinfo(1), histo(1), neaten(1), pcomb(1), rcalc(1), |
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rcollate(1), rcontrib(1), rfluxmtx(1), rlam(1), |
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rsplit(1), tabfunc(1), total(1), wrapBSDF(1) |
