Formula and fractions in lyx - lyx

I want to write to following formulas in lyx: Ic = (Number of new cases in D)/P0 and this one TBM =(Total number of all-cause deaths in a given region over a specified period)/(Estimated total exposed population of the same region during the same period). can someone help me please

When you are in math mode, type \text and then space. Then start typing normal text. Or try "ctrl + M" (when you are already inside math mode). For more information, please read Help > Math. Inserting text is discussed there.

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what happens to Schweizer T-Norm when p goes to zero?

I am reading Jang's book of Neuro-Fuzzy and Soft Computing and in the 2nd chapter the author talks about Schweizer and Sklar T-Norm which is presented by this equation:
it's a handy T-norm. in the exercises (#20 page 45) it asks what would happen to the Tss(a,b,p) if p->0
In fact it asks to show that the whole equation is going to be just ab in the end.
I tried different things and at last, I used Ln but I got this: -1/p Ln(a^-p + b^-p) and I have no idea where to go from here!
can anybody suggest anything? thanks for your help.
p.s: is there any simple way of expanding Ln(x+y) generally?

Cant enter imaginary numbers in SageMathCloud

I am trying to simply enter the character "i" into SageMathCloud so that I can construct imaginary numbers, this is my syntax:
ran40 = matrix(QQ,2,2,[[2*i,-2],[3,4]])
show(ran40)
I am constructing a matrix so that I can compute the reduced-row echelon form. The first element that is 2*i just needs to be 2i but I keeping getting syntax errors, how do I enter i for an imaginary number into SageMathCloud? I cannot find an example anywhere on the internet, if anyone knows this syntax please do inform me.
Your problem is that you decided what the ring is, and that ring doesn't have any imaginaries.
matrix(QQ,2,2,[[2*i,-2],[3,4]])
QQ is the rationals (the fraction field of ZZ, if you like).
Is this what you want? It will make things in the "symbolic ring" which can be slow...
M = matrix(2,2,[[2*i,-2],[3,4]])
show(M)
show(M.echelon_form())
show(M.rref())

TI-84: Same formula, same inputs, different answers when using program v.s. home screen

I wanted to write a simple formula in TI-Basic to calculate compound interest for my TI-84 calculator. The formula for compound interest is A = P(1+(r/n))^(n)(t) where p is the principal amount, r is the interest rate (expressed as a decimal), n is the number of times the principal is compounded, t is the amount of time, and a is your final amount with interest added.
When I set variables (see below) and and type the formula in exactly how it is above on my calculators home screen, I get $7332.86, which is the correct answer.
However, when I set the variables and type the formula in as a program (see below), I get $42684.69, which is not correct.
I have tried this program on 2 different TI-84 calculators and I have gotten the same results, so it is not something with my calculator.
I am honestly stumped. I have no idea why this is happening, so if you are good at math, know how to program a ti series calculator, or just see a mistake that I am missing, please tell me because this thing has been driving me crazy!
Program with same inputs and formula but gives different answer than when used on the home screen:
: 2000 -> P
: 0.065 -> R
: 54 -> N
: 20 -> T
: P(1+(R/N))^(N)(T) -> A
: Disp A
I don't exactly know what the problem you are facing is, but I think your program should look like this:
Prompt P
Prompt R
Prompt N
Prompt T
Disp P(1+(R/N))^(NT)
EDIT
I think you need an extra set of parentheses. ^(N)(T) only raises to the power of N, and then multiplies by T. Try ^((N)(T)) or simply ^(NT).
You're formula is equivalent to T*P*((1+(R/N))^(N)), which is obviously wrong. The reason it's doing this is because of the order of operations. Try P*(1+(R/N))^(T*N)
A shorter version of the code (if you want to conserve memory space):
:promptP,R,N,T
:Disp P(1+(R/N))^(NT)
Happy coding!

FastICA and Blind Signal Separation Mathematics Question

I'm trying to make my own implementation of the FastICA algorithm based on the paper here: http://www.cs.helsinki.fi/u/ahyvarin/papers/NN00new.pdf.
I need some help w/ the math though.
In the middle of page 14 there is an equation that looks somewhat like
w+ = E{ xg(w^Tx) } - E{ g[prime]( w^T x)} w
What does the E mean? Back from my probability days I recall that it is the "expected value" of a random variable but it doesn't make sense to me what the expected value of a vector is.
Thanks,
mj
ICA is interesting stuff. I used it some in my graduate research, but I didn't dig in too much under the hood; I just downloaded the FastICA implementation for MatLab and used that.
Anyway, you are correct that E{...} denotes expected value. The elements of the vector x represent the individual signals. Strictly speaking, x is a time series and should be written x(t), but the convention in ICA is to treat x instead as a random variable. In that context, of course, the idea of expected value makes sense. For example E{x} would just be the mean value of x (taken to be zero in ICA as the signals have been centered).
The authors of the paper you linked also have a book on ICA. It's outrageously expensive on Amazon, but if you can find a copy at, say, a nearby university library, it might be worth a look. It's been several years, but I remember it as being as gentle an introduction as one could hope for given the mathematics.

Checking every possible alphabet cipher combination

I've got what I think is a cipher (this isn't homework, just a challenge I thought I'd try to solve via coding for fun) which is:
"uiw uiw n la ltid mtel teacyihr n heeig sfsst"
To try to solve it, I'd like to iterate over every possible combination of cipher assignments for every letter in the alphabet (in an obviously brute force fashion), but I can't figure out an elegant way of going about that. Once I get the current iteration of the cipher assignment, I figure I'll transform the cipher text according to the cipher and then compare the first 3-letter word to a 3-letter wordlist and the last two words to a five letter wordlist, and if all three check out as being actual words, I'll have it print the results to file. This should give me a list of reasonable starting points to be able to weed out the incorrect results. If anyone has any ideas on how to go about implementing the iterative cipher I'd greatly appreciate it. Many thanks,
Peabody
You can have 26 for loop.
OK. I am kidding.
An obvious but inefficient version in pseudo code:
for i = 0 - 26^26-1
/* a = i/26^25 % 26
...
z = i/26^0 % 26 */
if all deciphered words are in the word list
print
end if
end for
By the way, I do not think it is the right way to decipher as said in your question, because I cannot find an example of double presence of a same word in an English sentence.

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