blocks|key|1705956|text|默认情况下，i和j代表虚数单位。因此，从MATLAB的角度来看，使用i作为变量与使用1作为变量有些相似。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|1705957|entityMap^0|6|1|8|1|Y|1|16|1|0^^$0|@$1|2|3|4|5|6|7|H|8|@$9|I|A|J|B|C]|$9|K|A|L|B|C]|$9|M|A|N|B|C]|$9|O|A|P|B|C]]|D|@]|E|$]]|$1|F|3|-4|5|6|7|Q|8|@]|D|@]|E|$]]]|G|$]]

By default <code>i</code> and <code>j</code> stand for the imaginary unit. So from MATLAB's point of view, using <code>i</code> as a variable is somehow like using <code>1</code> as a variable.

blocks|key|1919670|text|有人指出，1i是一种可接受的、明确的编写sqrt(-1)的方法，因此没有必要避免使用i。同样，作为Dennis+pointed+out，很难看出1i和ii之间的区别。我的建议是:尽可能使用1j作为假想常量。这是电气工程师使用的相同技巧-他们将j用于sqrt(-1)，因为i已经被认为是current。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|1919671|就我个人而言，我从不使用i和j；我使用ii和jj作为速记索引变量，(以及kk，ll，mm，...)当我需要使用复数时，使用1j。|1919672|entityMap|0|LINK|mutability|MUTABLE|url|https://stackoverflow.com/questions/14790740/using-i-and-j-as-variables-in-matlab/14893729#14893729|1|https://en.wikipedia.org/wiki/Electric_current^0|5|2|K|8|16|1|20|2|23|2|2M|2|3D|1|3G|8|3R|1|1D|I|0|3Y|7|1|0|C|1|E|1|J|2|M|2|1P|2|0^^$0|@$1|2|3|4|5|6|7|R|8|@$9|S|A|T|B|C]|$9|U|A|V|B|C]|$9|W|A|X|B|C]|$9|Y|A|Z|B|C]|$9|10|A|11|B|C]|$9|12|A|13|B|C]|$9|14|A|15|B|C]|$9|16|A|17|B|C]|$9|18|A|19|B|C]]|D|@$9|1A|A|1B|1|1C]|$9|1D|A|1E|1|1F]]|E|$]]|$1|F|3|G|5|6|7|1G|8|@$9|1H|A|1I|B|C]|$9|1J|A|1K|B|C]|$9|1L|A|1M|B|C]|$9|1N|A|1O|B|C]|$9|1P|A|1Q|B|C]]|D|@]|E|$]]|$1|H|3|-4|5|6|7|1R|8|@]|D|@]|E|$]]]|I|$J|$5|K|L|M|E|$N|O]]|P|$5|K|L|M|E|$N|Q]]]]

It was pointed out that <code>1i</code> is an acceptable and unambiguous way to write <code>sqrt(-1)</code>, and that as such there is no need to avoid using <code>i</code>. Then again, as <a href="https://stackoverflow.com/questions/14790740/using-i-and-j-as-variables-in-matlab/14893729#14893729">Dennis pointed out</a>, it can be hard to see the difference between <code>1i</code> and <code>ii</code>. My suggestion: use <code>1j</code> as the imaginary constant where possible. It's the same trick that electrical engineers employ - they use <code>j</code> for <code>sqrt(-1)</code> because <code>i</code> is already taken for <a href="https://en.wikipedia.org/wiki/Electric_current" rel="nofollow noreferrer">current</a>.
Personally I never use <code>i</code> and <code>j</code>; I use <code>ii</code> and <code>jj</code> as shorthand indexing variables, (and kk, ll, mm, ...) and <code>1j</code> when I need to use complex numbers.

blocks|key|1919726|text|任何重要的代码都包含多个for循环，最佳实践建议您使用描述性名称来表示其用途和范围。在很久以前(除非我不打算保存它的5-10行脚本)，我一直使用像idxTask，idxAnotherTask和idxSubTask这样的变量名。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|1919727|或者至少将它索引的数组的第一个字母加倍，例如ss索引subjectList，tt索引taskList，但不是ii或jj，这不能帮助我毫不费力地从我的多个for循环中识别出它们索引的是哪个数组。|1919728|entityMap^0|C|3|21|7|29|E|2O|A|0|M|2|Q|B|12|2|16|8|1I|2|1L|2|0^^$0|@$1|2|3|4|5|6|7|J|8|@$9|K|A|L|B|C]|$9|M|A|N|B|C]|$9|O|A|P|B|C]|$9|Q|A|R|B|C]]|D|@]|E|$]]|$1|F|3|G|5|6|7|S|8|@$9|T|A|U|B|C]|$9|V|A|W|B|C]|$9|X|A|Y|B|C]|$9|Z|A|10|B|C]|$9|11|A|12|B|C]|$9|13|A|14|B|C]]|D|@]|E|$]]|$1|H|3|-4|5|6|7|15|8|@]|D|@]|E|$]]]|I|$]]

Any non-trivial code contains multiple <code>for</code> loops, and the best practices recommend you use a descriptive name indicative of its purpose and scope. For times immemorial (and unless its 5-10 lines script that I am not going to save), I have always been using variable names like <code>idxTask</code>, <code>idxAnotherTask</code> and <code>idxSubTask</code> etc. 

Or at the very least doubling the first letter of the array it is indexing e.g. <code>ss</code> to index <code>subjectList</code>, <code>tt</code> to index <code>taskList</code>, but not <code>ii</code> or <code>jj</code> which doesn't help me effortlessly identify which array they are indexing out of my multiple for loops.

<code>i</code> and <code>j</code> are very popular variable names (see e.g., <a href="https://stackoverflow.com/questions/4137785/why-are-variables-i-and-j-used-for-counters">this question</a> and <a href="https://stackoverflow.com/questions/454303/why-are-we-using-i-as-a-counter-in-loops">this one</a>).
For example, in loops:
<pre><code>for i=1:10,
 % Do something...
end
</code></pre>
As indices into a matrix:
<pre><code>mat(i, j) = 4;
</code></pre>
Why shouldn't they be used as variable names in MATLAB?

Using i and j as variables in MATLAB

i和j是非常流行的变量名称(例如，请参阅和)。例如，在循环中：for i=1:10,    % Do something...end作为矩阵的索引：mat(i, j) = 4;为什么它们不能用作MATLAB中的变量名呢？

问在MATLAB中使用i和j作为变量
EN

社区

活动

资源

关于

腾讯云开发者

热门产品

热门推荐

更多推荐

问在MATLAB中使用i和j作为变量EN

社区

活动

资源

关于

腾讯云开发者

热门产品

热门推荐

更多推荐

问在MATLAB中使用i和j作为变量
EN