Parameter Filtering Specification

This guide explains how to use parameter specifications to select, filter, arrange, and exclude specific parameters or calculation outputs for display in tables, charts, and page layouts across qCalc.

Overview

Parameter specifications allow you to selectively display a subset of inputs or calculated results. You can specify parameters using:

• 1-based positional indices (e.g. 1, 3)
• Positional index ranges (e.g. 1-3, 3-1)
• Parameter names (case-insensitive, e.g. cost_chart, Gold)
• Parameter name ranges (e.g. arg2-arg5, cost_chart-total_price)
• Mixed name and index ranges (e.g. 2-cost_chart, cost_chart-5)
• Exclusions using the ~ prefix (e.g. ~3, ~vat_rate)
• Fractions / Proportions (e.g. 0.5 selects the first 50% of items)
• Wildcard (*) to include all items

Specifications can be supplied as a comma-separated string (e.g. "1-3, ~2"), a list of strings (e.g. ["1-3", "~2"]), or a numeric fraction.

Specification Syntax & Rules

1. Wildcard & Default (* / None)

To include all available parameters or results, use * or leave the specification empty (None).

# Selects all items
spec: "*"

2. Positional Selection (1-based Index)

Refer to parameters by their 1-based position in the input or output list.

Example:

For parameters [Width, Height, Depth, Weight, Price]: - "1-3" -> [Width, Height, Depth] - "3, 1" -> [Depth, Width]

3. Name-Based Selection & Wildcard Matching

Parameter names can be matched flexibly: - Case-Insensitive: GOLD, Gold, and gold all match the parameter gold. - Title Case & Display Names: Cost Chart matches cost_chart or cost_chart__r. - Result Suffixes: Names automatically resolve across result suffixes if any (e.g., __r, __rf, __ri, __rq). - Partial Pattern Matching (*): Use * anywhere within a string pattern to match parameter names (e.g. agr*nt matches argument, *cost* matches all cost columns).

4. Parameter Name Ranges

Ranges can be formed between parameter names, between positions, or mixing both.

5. Exclusions (~)

Prefix any item, position, or range with ~ to exclude it from the final selection.

Combination Examples:

• "1-5, ~3" -> Selects positions 1, 2, 4, 5 (excluding 3).
• "cost_chart-gold_value, ~vat_rate" -> Selects all items from cost_chart to gold_value, excluding vat_rate.

6. Fractions & Proportions

Supply a numeric value between 0 and 1 (exclusive) to select a proportion of total parameters.

Practical Examples for Visualizations & Layouts

Example A: Filtering Table Columns

Given calculation outputs: [Gold Weight, Gold Value, VAT on Gold, Making Charge, Grand Total]

# Display only Value, Making Charge, and Grand Total in the summary table
spec: "Gold Value, Making Charge, Grand Total"

# Or using exclusions to omit intermediate tax details:
spec: "1-5, ~VAT on Gold"

Example B: Customizing Chart Series

Given parameters: [Revenue, Cost of Goods, Gross Margin, Operating Expenses, Net Income]

# Select Revenue through Gross Margin, plus Net Income for the chart
spec: "Revenue-Gross Margin, Net Income"

Summary Cheat Sheet