- Chinese name
- Law of logarithm
- Foreign name
- Weber-Fechner law
- Alias
- Weber Fisher law
- Presenter
- fechner
- Applicable fields
- Mathematics, Statistics
- Applied discipline
- Elementary Mathematics, Advanced Mathematics, Psychology
- See publications
- Psychological Terms, Science Press
- Time of publication
- 1999 [3]
Lanchester equation Popularization of. In large-scale combat, when the number of troops (weapons) invested by each belligerent exceeds 15000, it is inappropriate to apply the linear law and the square law. At this time, the following equations need to be used: dB/dt=-aBlnR
dR/dt=-pRlnB
Under certain conditions, it can be simplified as
dB/dt=-aB
dR/dt=-pR
So there are
B=bexp（-at）
R=rexp（-pt）
This shows that the loss of one side's combat forces depends on their own initial strength and the consumption rate constants β and ρ, while the dependence on the other side's forces is very small [1]
Weber Fisher law: the law representing the functional relationship between sensory intensity and stimulus intensity [2] 。
Weber, a German physiologist, found that the new stimulus increment was proportional to the original stimulus (i.e. standard stimulus) when the difference of stimulus was just perceived.
Formula:
K=△I/I
It is called Weber's law, where △ I is the threshold of difference, I is the standard stimulus, and K is the constant ("Weber's constant").
On the basis of Weber's research, German physicist Fishner proposed that the size of sensation is proportional to the logarithm of stimulus intensity.
Formula:
S=KlgR
go by the name of Fechner's law Weber Fechner's Law or Logarithmic Law, where S represents sensory quantity, K represents constant, and R represents stimulus quantity. 
