Multiple Linear Least Squares Workbench
Fit a small multiple-predictor model with an intercept, stable centered residuals and transparent rank/orthogonality checks.
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How to use Multiple Linear Least Squares Workbench
Predictor columns are centered by origin shifts and scaled to unit norm. Twice-reorthogonalized modified Gram-Schmidt supplies QR without forming normal equations. Back substitution finds slopes; centered residual and QR checks must pass before fitted rows or entered predictions are exported.
- Enter predictor matrix json, response vector json, prediction matrix json (or []).
- Choose the stated convention and check the units and supported model.
- Calculate, inspect the result, then copy or download it.
Good to know
- 2–8 predictors, at least p+2 observations and at most 500 rows; up to 100 prediction rows. Numeric inputs have magnitude at most 1e9 and nonzero magnitude at least 1e-12. Constant or near-collinear columns with normalized QR diagonal at most 1e-8 are refused; coefficients above magnitude 1e15 are refused. Approximate arithmetic; the centered model is preferred when large origins cause an intercept to cancel. No p-values, confidence intervals, causal interpretation, regularization, missing data or extrapolation reliability claim.
- Local calculation only; no input persistence or external lookup. Text/JSON is limited to 30000 characters and output to 1000000 characters. Numeric model inputs and precision/work limits are stated on this page. Approximate JSON numbers retain full stored values; exact arithmetic outputs retain decimal or fraction strings. Unsupported states fail explicitly.
Common questions
Why reject nearly collinear predictors?
Many different coefficient vectors can then produce almost the same fitted values. Rather than display unstable slopes as precise, this bounded solver refuses the unsupported rank/precision state.
Is the input uploaded or saved?
No. The tool calculates inside this browser tab and provides a local download; it does not persist your input.
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