Dynamic Macroeconomic Modeling with Matlab

3 A Short Introduction to Matlab
Functions can be saved in m files in the same way as scripts. They have to be introduced
according to
function output = functionname(x1, x2)
where functionname is the name of the function, output is the function output, and x1, x2,
etc. are the input arguments. For example, the following function named test would yield the
square of the input argument x if executed
function output = test(x)
output=x*x;
>> test(3)
ans = 9
Exercises
1. sin, cos, exp, sqrt, pi, inf, NaN, i
Calculate
√ 2, √ −2,
2. size, eye, zeros, rand, randn, det, inv
cos(π) + 2 · e 0
sin(π) + 1 , sin(1010 · π),
1 −1
,
0 0 ,
Create two 3×3 matrices A and B with random entries equally distributed on the interval
[0; 10] and check, if
holds.
(A + I)(A − I) = A 2 − I
(A + B) t = A t + B t
(AB) t = B t A t
det(AB) = det(A) · det(B)
A −1 −1 = A
3. Define the parameters α = 0.3, β = 0.4, δ = 0.05, and A = 10 and calculate
for k = 1, 1.1, 1.2,...,3.
Ak α+β − δk
0
0