Tikz pgf

• How to Annotate a Slope Triangle in a PGFPlots Axis
  Draw a slope triangle in a PGFPlots axis with axis-coordinate segments and labels for the run, rise, and calculated slope.
• How to Fix “TeX Capacity Exceeded: Input Stack Size=5000”
  The TeX input stack error usually signals recursive macro or file input, not a diagram that is merely too large. Find the loop and fix its cause.
• Why Does an Arrow Disappear in a TikZ Draw Command?
  TikZ arrows can disappear when a path ends at a node center and the node covers the arrowhead. Use to or explicit shape anchors.
• How to Add a Label to a Plot in PGFPlots
  In PGFPlots, label a curve with \addlegendentry or annotate a point with a TikZ node placed at an axis coordinate.