| Abstract: | An extended form of Q-mode factor analysis may be used if the row-sums of the data matrix are constant and can be helpful especially in developing and testing petrologic-mixing models for igneous systems. The first step is to represent the sample compositions as unit vectors in M-dimensional space and then to project them into space of fewer dimensions (m) as determined to be appropriate from a factor-variance diagram. Compositions thought to be those of possible end-members in the petrologic system then are represented as vectors in the M-dimensional space and projected into the same space as the sample vectors. If these vectors remain close to unity in length after projection, the corresponding compositions can serve as end-member compositions for the model. After m suitable end-member compositions have been identified, each sample composition is expressed as a mixture of the end-members by computation of the composition loadings. The interactive computer programs presented are useful in these procedures because of the trial-and-error nature of the modeling procedures. ?? 1976. |
| Genre: | Article |
| ProdID: | 70010999 |
| Citation Author: | Miesch, A. T. |
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| Citation End Page: | 492 |
| Citation Issue: | 4 |
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| Citation Language: | English |
| Citation Larger Work Title: | Computers and Geosciences |
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| Citation Number Of Pages: | 54 |
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| Citation Publisher: | Elsevier |
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| Citation Search Results Text: | Interactive computer programs for petrologic modeling with extended Q-mode factor analysis; 1976; Article; Journal; Computers and Geosciences; Miesch, A. T. |
| Citation Start Page: | 439 |
| Citation Volume: | 2 |
| Citation Year: | 1976 |
| Type: | citation/reference |
| Text: | Interactive computer programs for petrologic modeling with extended Q-mode factor analysis; 1976; Article; Journal; Computers and Geosciences; Miesch, A. T. |
| URL (THUMBNAIL): | http://pubs.er.usgs.gov/thumbnails/outside_thumb.jpg |
| URL (DIGITAL OBJECT IDENTIFIER): | http://dx.doi.org/10.1016/0098-3004(76)90039-X |
| Date Other: | Thu, 1 Jan 1976 00:00 -0600 |
| Publisher: | Elsevier |
