[tune] Use scientific notation in tune dashboard (#8782)

Co-authored-by: Kai Fricke <kai@anyscale.com>

python/ray/dashboard/client/src/common/formatUtils.ts

@@ -30,3 +30,18 @@ export const formatDuration = (durationInSeconds: number) => {
     `${pad(durationSeconds)}s`,
   ].join(" ");
 };
+
+export const formatValue = (rawFloat: number) => {
+  try {
+    const decimals = rawFloat.toString().split(".")[1].length || 0;
+    if (decimals <= 3) {
+      return rawFloat.toString();
+    } // Few decimals
+    if (Math.abs(rawFloat.valueOf()) >= 1.0) {
+      return rawFloat.toPrecision(5);
+    } // Values >= 1
+    return rawFloat.toExponential(); // Values in (-1; 1)
+  } catch (e) {
+    return rawFloat.toString();
+  }
+};

python/ray/dashboard/client/src/pages/dashboard/tune/TuneTable.tsx

@@ -21,6 +21,7 @@ import React from "react";
 import { connect } from "react-redux";
 import { TuneTrial } from "../../../api";
 import DialogWithTitle from "../../../common/DialogWithTitle";
+import { formatValue } from "../../../common/formatUtils";
 import NumberedLines from "../../../common/NumberedLines";
 import { StoreState } from "../../../store";
 import { dashboardActions } from "../state";
@@ -387,7 +388,9 @@ class TuneTable extends React.Component<
                       </TableCell>
                       {viewableParams.map((value, index) => (
                         <TableCell className={classes.cell} key={index}>
-                          {trial["params"][value]}
+                          {typeof trial["params"][value] === "number"
+                            ? formatValue(Number(trial["params"][value]))
+                            : trial["params"][value]}
                         </TableCell>
                       ))}
                       <TableCell className={classes.cell}>
@@ -396,7 +399,9 @@ class TuneTable extends React.Component<
                       {trial["metrics"] &&
                         viewableMetrics.map((value, index) => (
                           <TableCell className={classes.cell} key={index}>
-                            {trial["metrics"][value]}
+                            {typeof trial["metrics"][value] === "number"
+                              ? formatValue(Number(trial["metrics"][value]))
+                              : trial["metrics"][value]}
                           </TableCell>
                         ))}
                       <TableCell className={classes.cell}>

python/ray/dashboard/dashboard.py

@@ -875,7 +875,7 @@ class TuneCollector(threading.Thread):
 
             # round all floats
             for key in float_keys:
-                details[key] = round(details[key], 3)
+                details[key] = round(details[key], 12)
 
             # group together config attributes
             for key in config_keys: