Log–log plot: Difference between revisions

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Applications: changed statement about use of log-log lines and limited validity for estimating power laws
Revised wording for clarity and changed a link so that it points to a description of power functions, rather than monomials. Rationale for link change: "Power function" refers to the relationship among the variables on both sides of the equation. "Monomial" may refer to only the right side of the equation, it usually implies the exponent is a nonnegative integer, which is not required in this context, and monomials may also contain several independent variables.
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{{More citations needed|date=December 2009}}
[[Image:LogLog exponentials.svg|thumb|A log–log plot of ''y''&nbsp;=&nbsp;''x''&nbsp;(blue), ''y''&nbsp;=&nbsp;''x''<sup>2</sup>&nbsp;(green), and ''y''&nbsp;=&nbsp;''x''<sup>3</sup>&nbsp;(red).<br>Note the logarithmic scale markings on each of the axes, and that the log&nbsp;''x'' and log&nbsp;''y'' axes (where the logarithms are 0) are where ''x'' and ''y'' themselves are 1.]]
In [[science]] and [[engineering]], a '''log–log graph''' or '''log–log plot''' is a two-dimensional graph of numerical data that uses [[logarithmic scale]]s on both the horizontal and vertical axes. [[MonomialExponentiation#Power_functions|Power functions]]s – relationships of the form <math>y=ax^k</math> – appear as straight lines in a log–log graph, with the power termexponent corresponding to the slope, and the constant termcoefficient corresponding to the intercept of the line. Thus these graphs are very useful for recognizing these relationships and [[estimating parameters]]. Any base can be used for the logarithm, though most commonly base 10 (common logs) are used.
 
== Relation with monomials ==