Matplotlib Zero Line - Time Series Mechanics

Read the Zero Line First

Start with four signed values: Returns is -3, Fees is 2, Discount is -1, and Sales is 4. Read the zero line before reading the bar direction. A bar above zero is positive. A bar below zero is negative. Fees and Sales are positive because their bars are above zero. Returns and Discount are negative because their bars are below zero.

A tiny chart-reading step: read the zero line before deciding whether bars or points are positive or negative.

highlighted = computed this step

Start with signed values

Start with 4 pinned signed values.

\text{signed values}

Find the zero line

Read the zero line before deciding positive or negative.

\text{zero line first}

Read bars around zero

Bars above zero are positive; bars below zero are negative.

\text{above and below zero}

Decide positive or negative

Fees and Sales are positive; Returns and Discount are negative.

\text{sign readout}