matplotlib: bring back plot() and linspace()

Author: piscisaureus

src/matplotlib.ts

@@ -0,0 +1,67 @@
+/*!
+   Copyright 2018 Propel http://propel.site/.  All rights reserved.
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+
+   http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+ */
+
+import { getOutputHandler, PlotData } from "./output_handler";
+import { isTensor } from "./util";
+
+export function plot(...args) {
+  if (!getOutputHandler()) {
+    console.warn("plot: no output handler");
+    return;
+  }
+
+  const xs = [];
+  const ys = [];
+  let state = "x";
+  for (let i = 0; i < args.length; i++) {
+    const arg = args[i];
+    switch (state) {
+      case "x":
+        xs.push(arg);
+        state = "y";
+        break;
+
+      case "y":
+        ys.push(arg);
+        state = "x";
+        break;
+    }
+  }
+
+  const nSeries = Math.min(xs.length, ys.length);
+  const data: PlotData = [];
+  for (let i = 0; i < nSeries; ++i) {
+    // TODO line = $.stack([xs[i], ys[i]], 1)
+    const xv = isTensor(xs[i]) ? xs[i].dataSync() : xs[i];
+    const yv = isTensor(ys[i]) ? ys[i].dataSync() : ys[i];
+    const nPoints = Math.min(xv.length, yv.length);
+    const line = [];
+    for (let j = 0; j < nPoints; ++j) {
+      line.push({ x: xv[j], y: yv[j] });
+    }
+    data.push(line);
+  }
+
+  getOutputHandler().plot(data);
+}
+
+export function linspace(start: number, stop: number, num: number): number[] {
+  const d = (stop - start) / (num - 1);
+  const values = new Array(num);
+  for (let i = 0; i <= num - 1; ++i) {
+    values[i] = start + i * d;
+  }
+  return values;
+}

src/sandbox.ts

@@ -16,6 +16,7 @@
 import * as test_internals from "./test_internals";
 
 import { fetchArrayBuffer } from "./fetch";
+import * as matplotlib from "./matplotlib";
 import { Transpiler } from "./nb_transpiler";
 import { setOutputHandler } from "./output_handler";
 import { RPC, WindowRPC } from "./rpc";
@@ -33,6 +34,7 @@ const moduleCache: { [name: string]: any } = Object.create(null);
 async function importModule(target: string) {
   // Check whether module is a built-in.
   switch (target) {
+    case "matplotlib": return matplotlib;
     case "test_internals": return test_internals;
   }