For example, F x y z if I have an equation that looks like this, f of x, y, z.
打个比方,我有个这样的方程。
x y z And I have another equation f of x, y, z.
若我有另一个方程。
That's it. Again, these other p dxy dyz - or the d x y, d y z, those are going to be those more complicated linear combinations, you don't need to worry about them.
同样,这些p轨道,或者,它们是一些,很复杂的线性组合,你们,不用管它。
And just as with variables, you should use some common sense, some style here, and the function's name should X Y communicate what it does, calling it X or Y or Z is generally not all that helpful.
就像变量,你使用一些常识,一些类型,和函数名需要,传达它所做的事情,把它叫做,或者Z通常是没有什么用处的。
Once I've got that, you notice I can now define a polar point, same way. Notice I've now solved one of my problems, which is, in each one of these cases here, I'm creating both x y and radius angle values inside of there.
你们注意到我现在可以,定义一个极坐标点了,以同样的方式,请注意到现在,我已经解决了我的问题之一了,也就是,在这些例子中的每一个,我在里面都创建了x,y值。
Covariance is--we'll call it--now we have two random variables, so cov... I'll just talk about it in a sample term.
协方差是...我们有两个随机变量,x和y的协方差是,从样本的角度来说
He still incurred -C because he ran and he also has a cost of |x-y| because he doesn't like Mr. Y winning.
他同样有-C的收益因为他参加了竞选,且他还有|x-y|的成本,因为他不喜欢Y先生获胜
It's very important that x and y are human constructs and we're not wedded to any of them.
很重要的是 x 轴和 y 轴是人为设定的,且我们不能拘泥于它们
Suppose f of x, y, z equals k1, that is my equation, s1 and it gives me a solution s1.
假设我的方程是这样,然后给出了一个解。
Let's test it in all possible combinations of x and y and see if we get the right answer.
来测试并看看,返回的结果正确不正确。
All right, c p 1 dot y, x I've said assign that to the value 2, 2,0. So now c p 1 has inside of it an x and y value.
一个特定的版本,我现在命名了一个内置变量,并给它赋值了,我刚刚做的也就是给它。
The power of linearity is F=k1+k2 if I come across f of x, y, z equals k1 plus k2, if it is a linear equation, I don't have to go and solve it all over again.
线性的威力是,一个方程,如果它是个线性方程,那么我就不用再去解他了。
XYZ I might as well do it as x, y, z because we are talking about something that is going in three space.
我最好设成,因为我们在讨论,三维的事物。
So this is giving me now that template, better way of saying it, all right, a template now, for a point is x, y, radius, angle.
其他的方法来进行计算,但是这就是典型的我,要放置它们的地方,因此这就给了我一个模板。
X Y Z It's more interestingly named an X or Y or Z.
你也可以把它命名为。
I'm simply saying swap X with Y, but this 2 won't work, because where are X and Y defined?
我只简单地说交换X和Y,但是这两行不起作用,因为X和Y是在哪里定义的呢?
If its in Cartesian form I'll pass in an x and y and compute what a radius and angle is.
来得到的这个点,我都可以得到这个点的,全部的这种信息。
Now, suppose in fact these weren't x and y glued together, these were radius and angle glued together.
我实际也说过了,我在这里操作的是,和这两个点。
But he said the energy of an X-Y bond is going to be equal to the square root.
但他说XY键的键能,会等于XX键与YY键键能乘积的平方根。
They might very well be storing the addresses of memory elsewhere, but we just needed them as sort of a cheat sheet, a little address card to know where the original values x and y were.
它们存储在内存的其他地方是可以的,但是我们需要一个备忘单,一个地址卡,来知道,原始的值x和y是什么。
Y I'm not passing an x and I'm not passing a Y, &y I'm passing an ampersand x and ampersand y and can you take a guess as to what the ampersand operator must mean?
我不是传递X,也不是传递,我传递的是&x和,你们可以猜一猜,这个&符号是什么意思?
Y He's not returning A or B or temp, and definitely not X or Y; so he just did all of this work and yet that's it.
他不会返回A或B或temp,肯定也不是X或;,所以他刚才做了所有的工作,就是那样。
You've got to realize that in calculus, the symbols that you call x and y are completely arbitrary.
你应该明白在微积分中,选x还是y当符号是完全任意的
Initially, its location as a function of time is equal to i times x plus j times y.
初始时刻,它的位移作为时间的函数等于,i ? x + j ? y
And actually, if I don't want to clobber, as we say, overwrite the value of my variable, ; I could declare another one and store the return value in Y; Y so now I have two ints in memory; X and Y, 3 one with two, one with three.
实际上,如果你不想彻底清除,像我们说的,覆盖那个变量的值,我可以申明另一个变量Y,并在Y中保存那个返回值;,现在内存中有两个int数,X和,一个的值为2,一个为。
Z So it would be incorrect to try to assign this to a variable X or Y or Z, because it doesn't actually give me anything back.
这个是错误的,来赋值这个给变量X或Y或,因为它的确没有返回什么给我。
Then, I gave you one other very important example of a particle moving in the x-y plane.
下面我再拿一个重要的例子,质点在 x-y 平面内的运动
What we can actually do is we could solve out for the X and for the Y.
实际上我们能够解出X和Y的值
Y You don't want to rename them L and R or X and Y right because you want to call them left and right.
你不想把它们重命名为L和R,或者X和,因为你想叫它们为left和。
So I don't know don't, John, I would argue if I'd written this better, I would have had a method that returned the x- and the y- value, and it would be cleaner to go after it that way.
我会去辩论这么写是不是更好,我也可以写一个,返回x坐标和y坐标的方法,这么做可能会更清楚一点,这是很棒的缩写,好。
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