quantified.uncertainty/squiggle
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

Prevent negative standard deviation in symbolic multiplication

Browse Source 
Introduced in #242
This commit is contained in:
Sam Nolan 2022-04-23 16:57:06 -04:00
parent dfd2f83c9d
commit ee6551a694
2 changed files with 4 additions and 3 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

1
packages/squiggle-lang/__tests__/ReducerInterface/ReducerInterface_Distribution_test.res
View File

@ -20,6 +20,7 @@ describe("eval on distribution functions", () => {
}) })
describe("unaryMinus", () => { describe("unaryMinus", () => {
testEval("mean(-normal(5,2))", "Ok(-5)") testEval("mean(-normal(5,2))", "Ok(-5)")
testEval("-normal(5,2)", "Ok(Normal(-5,2))")
}) })
describe("to", () => { describe("to", () => {
testEval("5 to 2", "Error(Math Error: Low value must be less than high value.)") testEval("5 to 2", "Error(Math Error: Low value must be less than high value.)")

6
packages/squiggle-lang/src/rescript/Distributions/SymbolicDist/SymbolicDist.res
View File

@ -52,7 +52,7 @@ module Normal = {
switch operation { switch operation {
| #Add => Some(#Normal({mean: n1 +. n2.mean, stdev: n2.stdev})) | #Add => Some(#Normal({mean: n1 +. n2.mean, stdev: n2.stdev}))
| #Subtract => Some(#Normal({mean: n1 -. n2.mean, stdev: n2.stdev})) | #Subtract => Some(#Normal({mean: n1 -. n2.mean, stdev: n2.stdev}))
| #Multiply => Some(#Normal({mean: n1 *. n2.mean, stdev: n1 *. n2.stdev})) | #Multiply => Some(#Normal({mean: n1 *. n2.mean, stdev: Js.Math.abs_float(n1) *. n2.stdev}))
| _ => None | _ => None
} }
@ -60,8 +60,8 @@ module Normal = {
switch operation { switch operation {
| #Add => Some(#Normal({mean: n1.mean +. n2, stdev: n1.stdev})) | #Add => Some(#Normal({mean: n1.mean +. n2, stdev: n1.stdev}))
| #Subtract => Some(#Normal({mean: n1.mean -. n2, stdev: n1.stdev})) | #Subtract => Some(#Normal({mean: n1.mean -. n2, stdev: n1.stdev}))
| #Multiply => Some(#Normal({mean: n1.mean *. n2, stdev: n1.stdev *. n2})) | #Multiply => Some(#Normal({mean: n1.mean *. n2, stdev: n1.stdev *. Js.Math.abs_float(n2)}))
| #Divide => Some(#Normal({mean: n1.mean /. n2, stdev: n1.stdev /. n2})) | #Divide => Some(#Normal({mean: n1.mean /. n2, stdev: n1.stdev /. Js.Math.abs_float(n2)}))
| _ => None | _ => None
} }
} }