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。

2. 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。

3. 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。

4. 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。

5. 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。