# quasiconcavity: Test for quasiconcavity / quasiconvexity In miscTools: Miscellaneous Tools and Utilities

 quasiconcavity R Documentation

## Test for quasiconcavity / quasiconvexity

### Description

Test wether a function is quasiconcave or quasiconvex. The bordered Hessian of this function is checked by `quasiconcavity`() or `quasiconvexity`().

### Usage

``````   quasiconcavity( m, tol = .Machine\$double.eps )
quasiconvexity( m, tol = .Machine\$double.eps )
``````

### Arguments

 `m` a bordered Hessian matrix or a list containing bordered Hessian matrices `tol` tolerance level (values between `-tol` and `tol` are considered to be zero).

### Value

locigal or a logical vector (if `m` is a list).

Arne Henningsen

### References

Chiang, A.C. (1984) Fundamental Methods of Mathematical Economics, 3rd ed., McGraw-Hill.

### Examples

``````   quasiconcavity( matrix( 0, 3, 3 ) )

quasiconvexity( matrix( 0, 3, 3 ) )

m <- list()
m[[1]] <- matrix( c( 0,-1,-1, -1,-2,3, -1,3,5 ), 3, 3 )
m[[2]] <- matrix( c( 0,1,-1, 1,-2,3, -1,3,5 ), 3, 3 )

quasiconcavity( m )

quasiconvexity( m )
``````

miscTools documentation built on May 3, 2023, 5:11 p.m.