hi i started the matlab onramp course and im stuck on this further practice question i wld appreciate if anyone cld help me or even give an hint

Question

areeb 2024-8-22，11:13

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/2147184-hi-i-started-the-matlab-onramp-course-and-im-stuck-on-this-further-practice-question-i-wld-appreciat

评论： areeb 2024-8-22，15:03

3 个评论
显示 1更早的评论隐藏 1更早的评论

Image Analyst 2024-8-22，13:33

That is not a question. It's just giving you information. For a demo of that, see the Answer below (scroll down) or show us the actual question.

Sahas 2024-8-22，14:08

Hi @areeb,

From what I assume you may be trying this.

请先登录，再进行评论。

请先登录，再回答此问题。

Answer 1

Fangjun Jiang 2024-8-22，12:54

在 MATLAB Online 中打开

density=10:10:100
density = 1x10
    10    20    30    40    50    60    70    80    90   100
<mw-icon class=""></mw-icon>
<mw-icon class=""></mw-icon>
index=[1 3 6]
index = 1x3
     1     3     6
<mw-icon class=""></mw-icon>
<mw-icon class=""></mw-icon>
SelectedDensityValue=density(index)
SelectedDensityValue = 1x3
    10    30    60
<mw-icon class=""></mw-icon>
<mw-icon class=""></mw-icon>

0 个评论
显示 -2更早的评论隐藏 -2更早的评论

请先登录，再进行评论。

Answer 2

Steven Lord 2024-8-22，14:08

在 MATLAB Online 中打开

As Image Analyst stated, it's an informational message not a question. Its intent is to let you know that the indices you use to index into an array in MATLAB need not refer to a contiguous section of the array. [They can, but they're not required to.]

x = (1:10).^2 % original array into which you want to index
x = 1x10
     1     4     9    16    25    36    49    64    81   100
<mw-icon class=""></mw-icon>
<mw-icon class=""></mw-icon>
contiguous = x([4 5 6]) % a section of x from the middle
contiguous = 1x3
    16    25    36
<mw-icon class=""></mw-icon>
<mw-icon class=""></mw-icon>

You can skip elements.

skip = x(1:2:end) % get every other element of x
skip = 1x5
     1     9    25    49    81
<mw-icon class=""></mw-icon>
<mw-icon class=""></mw-icon>

You can repeat elements.

repeated = x([3 5 5 7]) % 25 appears twice in the output
repeated = 1x4
     9    25    25    49
<mw-icon class=""></mw-icon>
<mw-icon class=""></mw-icon>

You can specify indices that aren't sorted.

unsorted = x([1 4 7 10 2:3:8 3 6 9]) % "shuffle" the elements
unsorted = 1x10
     1    16    49   100     4    25    64     9    36    81
<mw-icon class=""></mw-icon>
<mw-icon class=""></mw-icon>

In this last section I used the "skip" pattern as part of generating the unsorted list. I could have done that slightly more compactly by using it for all three sections.

unsorted2 = x([1:3:10 2:3:8 3:3:9]) % "shuffle" the elements
unsorted = 1x10
     1    16    49   100     4    25    64     9    36    81
<mw-icon class=""></mw-icon>
<mw-icon class=""></mw-icon>