How safe are self-driving cars yet regarding total use and accident rate?

Does anyone have any data on that topic? If a self-driving cars happens to be in an accident every news site is talking about it, but many car accidents happen all the time sadly. So are they safer than normal cars yet if you compare?

submitted by Nevin Manimala Nevin Manimala /u/FXelix
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How can we find the maximal k dimensional cross section of a d dimensional hypercube?

Suppose we have a d-hypercube whose 2d vertices are those whose coordinates are either 1 or -1. Which k hyperplane can we construct such that its intersection with the cube will have maximal k-volume.

For example if we have d=2 and k =1 how can we construct a line such that it intersects the square (whose vertices are of the form (+-1, +-1) ) such that the intersection has maximal length? The line is a line that goes through two opposite vertices of the square.

How does this generalise to all regular polytopes is my main question. Any ideas/sources appreciated!!

submitted by Nevin Manimala Nevin Manimala /u/thenumbernumber
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How to check if time series is stationary? (with R programming language)

Hi guys, I must test stationarity of a time series. I use the function adf.test(timeSeriesData) {aTSA}, this function return a result the contains 3 components:

  • type1 (a matrix with three columns: lag, ADF, p.value, where ADF is the Augmented Dickey-Fuller test statistic)
  • type2 (same as above for the second type of linear model)
  • type3 (same as above for the second type of linear model)

If p.value < 0.05 the time series is stationarity. My problem is: which is the difference between type1, 2 and 3? In which case do I use the type X?

Thanks for your answers!


result <- adf.test(signals[[nameOfSignal]]$data , output = FALSE) if(result$type1[,3]< 0.05){ print("Is stationary") 

submitted by Nevin Manimala Nevin Manimala /u/FuocoNegliOcchi
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curiosity on parallel lines and spheres

so…first: I’m not a math expert, second: I think this topic is moar like geometry but anyway…

if we have 2 parallel lines on a sphere they meet at the poles right? like the Longitudes of the earth. said this if we start “squashing” the sphere the lines keep on touching at the poles. if we keep doing this until we have something so similar to a plane that it is indistinguishable from it, the lines still meet at the pole… so is it right to say that parallel lines actually do meet…? and why doesn’t this happen for the latitude of the earth? because of technically speaking they to have the same proprieties of the longitudes.

submitted by Nevin Manimala Nevin Manimala /u/TheCubeMan4
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Not a homework/cheating question

Hi, I need to prepare for a test, and this is one of the questions on a practice paper. I am not cheating – I merely want to prepare for my test. Hopefully this qualifies here.

  1. (15 points) Sheldon, Leonard, Raj and Howard have decided to become silent partners in Stuarts comic book empire. One of their first decisions is about opening hours at the weekend. Over one Saturday they have counted the number of customers in the shop in regular intervals of 10 minutes. Can we assume that the frequency of visitors follows a Poisson distribution? Here are the observations:

Number of customers xi 0 1 2 3 4 5 6+

Number of intervals with xi customers 5 7 10 11 5 6 4

I’m clueless here – what do I do? Don’t solve it – just tell me what to do. Does this thing follow a poisson distribution? I checked online and the questions I found all have something like an average rate of whatever/time. How do I find that out here? The last number is 6+(6 and more) so I can’t find any average rates here, can I?

Any help is much appreciated.

submitted by Nevin Manimala Nevin Manimala /u/pushkar000
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Check out this visualization of Newtons method working in multiple dimensions:

submitted by Nevin Manimala Nevin Manimala /u/rohitpandey576
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