For a log y-axis, create any chart with a y axis (other than a 3D surface
chart). Double-click the y-axis, from the Scale tab check the option for
'Logarithmic scale'.

FOr a log x-axis, create a XY Scatter chart, double-click the x-axis, and
from the Scale tab check the option for 'Logarithmic scale'.

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Regards,

Tushar Mehta
www.tushar-mehta.com
Excel, PowerPoint, and VBA add-ins, tutorials
Custom MS Office productivity solutions

In article ,
says...
excel should have charts that use semi log graph paper

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