avg

Instructions

Implementation Reference

• cruncher.js:573-590 (schema)

  Input schema definition for the 'avg' tool. Takes an array of numbers and computes the average (mean).

  {
      name: "avg",
      annotations: {
          title: "Average",
          readOnlyHint: true,
          destructiveHint: false,
          idempotentHint: true,
          openWorldHint: false,
      },
      description: "Average (mean) of numbers.",
      inputSchema: {
          type: "object",
          properties: {
              numbers: { type: "array", items: { type: "number" } },
          },
          required: ["numbers"],
      },
  },

• cruncher.js:1529-1536 (handler)

  Handler function for the 'avg' tool. Computes the arithmetic mean of an array of numbers using safeMath.add and safeMath.divide to avoid floating-point errors. Throws if the array is empty.

  avg: ({ numbers }) => {
      if (numbers.length === 0)
          throw new Error("Cannot calculate the average of an empty list.");
      return safeMath.divide(
          numbers.reduce((acc, val) => safeMath.add(acc, val), 0),
          numbers.length,
      );
  },

• cruncher.js:82-82 (registration)

  Tool name 'avg' registered in the 'standard' tier of the TOOL_TIERS configuration. This controls which tool set is exposed based on the CRUNCHER_TOOL_SET environment variable.

  "sum", "avg", "min", "max", "count", "variance", "std_dev",

• cruncher.js:1244-1294 (helper)

  The safeMath helper object, used by the avg handler to safely add and divide numbers with integer-scaling to avoid floating-point precision errors.

  const safeMath = {
      add: (a, b) => {
          const d1 = countDecimals(a);
          const d2 = countDecimals(b);
          const maxDecimals = Math.max(d1, d2);
          const multiplier = Math.pow(10, maxDecimals);
          return (
              (Math.round(a * multiplier) + Math.round(b * multiplier)) /
              multiplier
          );
      },
      subtract: (a, b) => {
          const d1 = countDecimals(a);
          const d2 = countDecimals(b);
          const maxDecimals = Math.max(d1, d2);
          const multiplier = Math.pow(10, maxDecimals);
          return (
              (Math.round(a * multiplier) - Math.round(b * multiplier)) /
              multiplier
          );
      },
      multiply: (a, b) => {
          const d1 = countDecimals(a);
          const d2 = countDecimals(b);
          const multiplier1 = Math.pow(10, d1);
          const multiplier2 = Math.pow(10, d2);
          return (
              (Math.round(a * multiplier1) * Math.round(b * multiplier2)) /
              (multiplier1 * multiplier2)
          );
      },
      divide: (a, b) => {
          if (b === 0) throw new Error("Division by zero is not allowed.");
          const d1 = countDecimals(a);
          const d2 = countDecimals(b);
          const maxDecimals = Math.max(d1, d2);
          const multiplier = Math.pow(10, maxDecimals);
          return Math.round(a * multiplier) / Math.round(b * multiplier);
      },
      modulo: (a, b) => {
          if (b === 0) throw new Error("Modulo by zero is not allowed.");
          const d1 = countDecimals(a);
          const d2 = countDecimals(b);
          const maxDecimals = Math.max(d1, d2);
          const multiplier = Math.pow(10, maxDecimals);
          return (
              (Math.round(a * multiplier) % Math.round(b * multiplier)) /
              multiplier
          );
      },
  };