Add types for distributions (#31472)

* Add types for distributions

* Fix import

types/distributions/distributions-tests.ts

@@ -0,0 +1,17 @@
+import * as distributions from 'distributions';
+
+const normal = distributions.Normal();
+normal.cdf(0);
+normal.pdf(0);
+normal.inv(0);
+normal.mean();
+normal.median();
+normal.variance();
+
+const uniform = distributions.Uniform();
+uniform.cdf(0);
+uniform.pdf(0);
+uniform.inv(0);
+uniform.mean();
+uniform.median();
+uniform.variance();

types/distributions/index.d.ts

@@ -0,0 +1,18 @@
+// Type definitions for distributions 2.0
+// Project: https://github.com/AndreasMadsen/distributions
+// Definitions by: Marco Lanaro <https://github.com/marcolanaro>
+// Definitions: https://github.com/DefinitelyTyped/DefinitelyTyped
+
+export function Normal(mean?: number, sd?: number): Distribution;
+export function Studentt(df: number): Distribution;
+export function Uniform(a?: number, b?: number): Distribution;
+export function Binomial(properbility: number, size: number): Distribution;
+
+export interface Distribution {
+    pdf: (x: number) => number;
+    cdf: (x: number) => number;
+    inv: (p: number) => number;
+    mean: () => number;
+    median: () => number;
+    variance: () => number;
+}

types/distributions/tsconfig.json

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+{
+    "compilerOptions": {
+        "module": "commonjs",
+        "lib": [
+            "es6"
+        ],
+        "noImplicitAny": true,
+        "noImplicitThis": true,
+        "strictNullChecks": true,
+        "strictFunctionTypes": true,
+        "esModuleInterop": true,
+        "baseUrl": "../",
+        "typeRoots": [
+            "../"
+        ],
+        "types": [],
+        "noEmit": true,
+        "forceConsistentCasingInFileNames": true
+    },
+    "files": [
+        "index.d.ts",
+        "distributions-tests.ts"
+    ]
+}

types/distributions/tslint.json

@@ -0,0 +1 @@
+{ "extends": "dtslint/dt.json" }