== 实验目的 ==
熟悉MATLAB的实验环境，掌握MATLAB基本的使用方法

== 预备知识 ==
参见：[[熟悉MATLAB环境]]

== 实验任务 ==

 1. MATLAB 没有提供一个函数来确定数组的每个元素是不是整数（即...,-2,-1,0,1,2,...）。写一个函数来实现这个功能，并满足下面的格式：{{{
function I = isinteger(A)
%ISINTEGER Determines which elements of an array are integers.
%        I = ISINTEGER(A) returns a logical array, I, of the same size
%        as A, with 1s (TRUE) in the locations corresponding to integers
%        (i.e., . . . -2 -1 0 1 2 . . . )in A, and 0s (FALSE) elsewhere.
%        A must be a numeric array.
}}}要求不能使用while或者for循环。提示：使用floor函数。如果你要做到能够处理复数，那么可以使用real和imag函数。

 1. MATLAB没有提供一个函数用来确定数组的每个元素是不是偶数（即...,-4,-2,0,2,4,...）。写一个函数来实现这个功能，并满足下面的格式：{{{
function E = iseven(A)
%ISEVEN Determines which elements of an array are even numbers.
%     E = ISEVEN(A) returns a logical array, E, of the same size as A,
%     with 1s (TRUE) in the locations corresponding to even numbers
%     (i.e., ... -4, -2, 0, 2, 4, ... )in A, and 0s (FALSE) elsewhere.
%     A must be a numeric array.
}}}要求不能使用while或者for循环。提示：使用floor函数。
 1. MATLAB没有提供一个函数用来确定数组的每个元素是不是奇数（即...,−3,−1,1,3,...）。写一个函数实现这个功能，并满足下面的格式：{{{
function D = isodd(A)
%ISODD Determines which elements of an array are odd numbers.
%      E = ISODD(A) returns a logical array, D, of the same size as A,
%      with 1s (TRUE) in the locations corresponding to odd numbers
%    (i.e., . . . -3, -1, 1, 3, . . . )in A, and 0s (FALSE) elsewhere.
%    A must be a numeric array.
}}}要求不能使用while或者for循环。提示：使用floor函数。
 1. 写一个函数满足下面的规定：{{{
function H = imcircle(R, M, N)
%IMCIRCLE Generates a circle inside a rectangle.
%    H = IMCIRCLE(R, M, N) generates a circle of radius R centered
%    on a rectangle of height M and width N. H is a binary image with
%    1s on the circle and 0s elsewhere. R must be an integer >= 1.
}}}你的程序应该检查R的合理性，使它能够在矩形的内部。要求不能使用for或者while循环。提示：使用函数meshgrid和floor函数。
 1. 这个实验主要目的是学习如何显示和改变目录，并利用目录信息来读取图像。写一个函数满足下面的规定：{{{
function [I, map] = imagein(path)
%IMAGEIN Read image in from current-working or specified directory.
%     I = IMAGEIN displays a window containing all the files in the
%     current directory, and saves in I the image selected from the
%     current directory.
%     [I, MAP] = IMAGEIN variable MAP is required to be an output
%     argument when the image being read is an indexed image.
%     [ . . .] = IMAGEIN('PATH') is used when the image to be read
%     resides in a specified directory. For example, the input
%     argument 'C:\MY_WORK\MY_IMAGES' opens a window showing
%     the contents of directory MY_IMAGES. An image selected from
%     that directory is read in as image I.
}}}提示：使用在线帮助来熟悉cd，pwd，uigetfile函数的使用。或者也可以采用fullfile函数来代替cd函数。