Charts & Data Visualization
Radar (Spider) Chart Formula: 0–100 Multi-Axis Normalization & Polygon Area
Normalize incommensurate KPI units (dollars, milliseconds, percentages) onto a common 0–100 Radar / Spider Chart spoke scale (with polarity inversion for lower-is-better metrics) and compute enclosed K-spoke polygon area.
Never plot raw milliseconds next to percentages on a Radar Chart without 0–100 spoke normalization!
A Radar (Spider / Web / Kiviat) Chart plots K multivariate performance dimensions as radial spokes around a central hub! If Spoke 1 is API Latency (240 ms) and Spoke 2 is Uptime (0.999), unscaled spokes collapse Uptime invisibly into the center while higher-is-worse Latency pushes outward as if slow response were good! Every Radar spoke must be normalized onto a common 0–100 higher-is-better scale:
For Higher-is-Better spokes (Throughput, NPS, Uptime): Score = 100 * (Actual - Worst_Min) / (Best_Max - Worst_Min)! For Lower-is-Better spokes (Cost, Defect Rate, Latency): Score = 100 * (Worst_Max - Actual) / (Worst_Max - Best_Min)! Once normalized to radii r_1 .. r_K at equal central angle 2 * PI() / K, exact enclosed K-spoke Radar Polygon Area equals 0.5 * SIN(2 * PI() / K) * (r_1*r_2 + r_2*r_3 + ... + r_K*r_1)!
| Radar Spoke Dimension (4-Spoke Vendor Scorecard) | Raw Range [Worst -> Best] | Vendor Raw Value | Normalized 0–100 Spoke Score |
|---|---|---|---|
| Spoke 1: Throughput (Higher Better) | 100 -> 500 req/s | 420 req/s | 80.0 |
| Spoke 2: P95 Latency (Lower Better!) | 400 -> 50 ms | 120 ms | 80.0 |
| Spoke 3: Security Audit (Higher Better) | 0 -> 100 pts | 90 pts | 90.0 |
| Spoke 4: Unit Cost (Lower Better!) | $2.00 -> $0.50 | $0.95 | 70.0 |
Polarity-Aware 0–100 Radar Spoke Normalization Formula
Maps Actual B2 between Benchmark_Low B3 and Benchmark_High B4 onto [0, 100], using Direction B5 = 1 for Higher-is-Better and B5 = -1 for Lower-is-Better.
=IF(OR(B4 <= B3, AND(B5 <> 1, B5 <> -1)), "Requires High > Low and Polarity +1 or -1", ROUND(100 * MIN(1, MAX(0, IF(B5 = 1, (B2 - B3) / (B4 - B3), (B4 - B2) / (B4 - B3)))), 2))Enclosed 4-Spoke Radar Polygon Area (0.5 * SIN(90°) * Cyclic Spoke Products)
For 4 orthogonal spokes (E2:E5 in [0, 100], where SIN(2*PI()/4) = SIN(90°) = 1), evaluates exact polygon area 0.5 * (r1*r2 + r2*r3 + r3*r4 + r4*r1) as % of maximum 20,000 square units.
=ROUND(100 * (0.5 * (E2 * E3 + E3 * E4 + E4 * E5 + E5 * E2)) / 20000, 2)Try the example
Use the original values or change them to test your understanding.