
Avoiding Misleading Axes in Excel Charts Built From Data
Avoid misleading axes in Excel charts: start bars at zero, set scales on purpose, avoid dual axes, use consistent scales across charts and label the units.
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Avoid misleading axes in Excel charts: start bars at zero, set scales on purpose, avoid dual axes, use consistent scales across charts and label the units.

Export charts as PNG or SVG from a script: draw with matplotlib from the same data, render headless with LibreOffice, or use Windows COM.

Build an Excel dashboard from SQL output: one data sheet per query, a presentation sheet of tiles and charts, scheduled refresh and tie-out checks.

Add sparklines, data bars, color scales and icon sets to a table so readers can scan 40 rows in seconds, written from XlsxWriter with accessible choices.

Fix charts that miss new rows or show blank gaps when data size changes: Excel tables, dynamic named ranges, generated ranges and refresh settings.

Three ways to rewrite a renamed JSON property across 1.5 million events in PostgreSQL: one UPDATE, batches and a table swap, with WAL, bloat and leftovers.

Fix invalid input syntax for type numeric on a JSON property that became a string, null or object, with jsonb_typeof, pg_input_is_valid and a function.

Expression, partial and GIN indexes on a 2.25 million row jsonb event table: a selective lookup fell from 65 ms to 5 ms, a 4 percent filter got slower.

A nightly job that turns jsonb event properties into a typed facts table in PostgreSQL: safe casts, a watermark, idempotent inserts and a 47x speedup.

Four designs for the same 500,000 purchase events compared on size and query time: verbose nesting, short flat keys, hybrid columns and key/value arrays.

Choose an Excel chart type from the shape of your query result: line, column, bar, stacked, scatter, histogram or table, with rules and the mistakes to avoid.

Build clear Excel charts from database data: shape the query, pick the chart, keep ranges live, avoid misleading axes, add sparklines, export images.
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