vpa — Evaluate scalar symbolic or numeric input as a symbolic decimal.
vpa(x) converts a scalar symbolic or numeric input to a scalar symbolic decimal literal using the current digits setting. vpa(x, d) uses d significant decimal digits. Exact symbolic rationals are expanded exactly; ordinary numeric inputs are rendered from the numeric value supplied by the script.
Syntax
vpa(x)How vpa works
- The default precision is controlled by
digitsand starts at 32 significant digits. - Exact rational symbolic inputs such as
sym('1/3')are expanded and rounded with the requested significant digits. - Numeric scalar inputs are converted to symbolic decimal literals from their existing numeric value at the requested display precision.
- Nonconstant symbolic variables remain symbolic.
- RunMat currently represents scalar symbolic expressions; array-valued symbolic containers are not materialized.
Examples
Render numeric pi at 50 digits
vpa(pi, 50)Expected output:
3.141592653589793...Evaluate an exact rational
vpa(sym('1/3'), 20)Expected output:
0.33333333333333333333Using vpa with coding agents
Open a RunMat example with live inputs, then ask the agent to explain how vpa changes the result.
Run a small vpa example, explain the result, then change one input and compare the output.
FAQ
Does vpa return a double?⌄
No. It returns a scalar symbolic value so formatting and downstream symbolic operations can preserve the decimal literal.
Related Math functions
Elementwise
abs · angle · complex · conj · double · exp · expm1 · factorial · gamma · heaviside · hypot · imag · ldivide · log · log10 · log1p · log2 · minus · nextpow2 · plus · pow2 · power · rdivide · real · sign · single · sqrt · times
Trigonometry
acos · acosh · asin · asinh · atan · atan2 · atanh · cos · cosd · cosh · deg2rad · rad2deg · sin · sind · sinh · tan · tand · tanh
Reduction
all · any · cummax · cummin · cumprod · cumsum · cumtrapz · diff · gradient · max · mean · median · min · nnz · prod · std · sum · trapz · var
Structure
Open-source implementation
Unlike proprietary runtimes, every RunMat function is open-source. Read exactly how vpa is executed, line by line, in Rust.
- View the source for vpa in Rust on GitHub
- Learn how the RunMat runtime works
- Found a bug? Open an issue with a minimal reproduction.
About RunMat
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