search for: x_3

Displaying 20 results from an estimated 23 matches for "x_3".

Did you mean: x3
2009 Jun 11
2
Optimization Question
Hi All Apologies if this is not the correct list for this question. The Rglpk package offers the following example in its documentation library(Rglpk) ## Simple mixed integer linear program. ## maximize: 3 x_1 + 1 x_2 + 3 x_3 ## subject to: -1 x_1 + 2 x_2 + x_3 <= 4 ## 4 x_2 - 3 x_3 <= 2 ## x_1 - 3 x_2 + 2 x_3 <= 3 ## x_1, x_3 are non-negative integers ## x_2 is a non-negative real number obj <- c(3, 1, 3) mat <- matrix(c(-1, 0, 1, 2, 4, -3, 1, -3, 2), nrow = 3) dir <- c("<=", "<=&...
2009 Dec 04
2
Solve linear program without objective function
Dear R-users, i try to solve to following linear programm in R 0 * x_1 + 2/3 * x_2 + 1/3 * x_3 + 1/3 * x_4 = 0.3 x_1 + x_2 + x_3 + x_4 = 1 x_1, x_2, x_3, x_4 > 0, x_1, x_2, x_3, x_4 < 1 as you can see i have no objective function here besides that i use the following code. library(lpSolve) f.obj<-c(1,1,1,1) f.con<-matrix(c(0,2/3,1/3,1/3, 1,1,1,1,...
2004 May 21
2
Help with Plotting Function
Dear List: I cannot seem to find a way to plot my data correctly. I have a small data frame with 6 total variables (x_1 ... x_6). I am trying to plot x_1 against x_2 and x_3. I have tried plot(x_2, x_1) #obviously works fine plot(x_3, x_1, add=TRUE) # Does not work. I keep getting error messages. I would also like to add ablines to this plot. I have experimented with a number of other plotting functions and I cannot seem to get this to work. The data are student...
2011 May 22
2
Finding solution set of system of linear equations.
...1 [2,] 3 0 0 4 [3,] 1 -4 -2 -2 [4,] 0 0 0 0 > b [,1] [1,] 0 [2,] 2 [3,] 2 [4,] 0 (This is ex Ch1, 2.2 of Artin, Algebra). So, 3 eqs in 4 unknowns. One can easily use row-reductions to find a homogeneous solution(b=0) of: X_1 = 0, X_2 = -c/2, X_3 = c, X_4 = 0 and solutions of the above system are: X_1 = 2/3, X_2 = -1/3-c/2, X_3 = c, X_4 = 0. So the Kernel is 1-D spanned by X_2 = -X_3 /2, (nulliity=1), rank is 3. In R I use solve(): > solve(a,b) Error in solve.default(a, b) : Lapack routine dgesv: system is exactly singular and i...
2012 Sep 05
2
Improvement of Regression Model
...folks, I am on learning phase of R. I have developed Regression Model over six predictor variables. while development, i found my all data are not very linear. So, may because of this the prediction of my model is not exact. Here is the summary of model : Call: lm(formula = y ~ x_1 + x_2 + x_3 + x_4 + x_5 + x_6) Residuals: Min 1Q Median 3Q Max -125.302 -26.210 0.702 26.261 111.511 Coefficients: Estimate Std. Error t value Pr(>|t|) (Intercept) 48.62944 0.27999 173.684 < 2e-16 *** x_1 -0.67831 0.08053 -8.423 < 2e-16 ***...
2014 Aug 21
2
[LLVMdev] Alias Analysis Semantics
...; > > This is not what it looks like in LLVM. > > In LLVM, it looks like this: > > std::vector<int> A(100); >> int* x,y; >> > >> > x_1=GEP A, 0, 0 >> > for(int i=0; i<100; i++) { >> > i_2 = phi (0, i_3) > x_2 = phi(x_1, x_3) > y_1 = GEP A, 0, i_2 > temp = load x_2 > store y_1, temp > temp2 = add i_2, 1 > x_3 = GEP A, 0, temp2 > i_3 = add i_2, 1 > } > > As you can see, every time you redefine the value of the pointer x to a > new value, it gets a new name. > >...
2006 Dec 08
1
MAXIMIZATION WITH CONSTRAINTS
...R users, I?m a graduate students and in my master thesis I must obtain the values of the parameters x_i which maximize this Multinomial log?likelihood function log(n!)-sum_{i=1]^4 log(n_i!)+sum_ {i=1}^4 n_i log(x_i) under the following constraints: a) sum_i x_i=1, x_i>=0, b) x_1<=x_2+x_3+x_4 c)x_2<=x_3+x_4 I have been using the ?ConstrOptim? R-function with the instructions I report below, and I have tried to implement them with different values of ?n?. BUT I have encountered 2 problems: 1) the result of the maximization is the same of the minimization, i.e. the maximum val...
2000 Oct 03
5
Where is gam?
I noticed that there is no generalised additive model functions in R (1.1.1) ... is there a package that implements them? Thanks Prasad ***************************************************************** Mr. Anantha Prasad, Ecologist/GIS Specialist USDA Forest Service, 359 Main Rd. Delaware OHIO 43015 USA Ph: 740-368-0103 Email: aprasad at fs.fed.us Web:
2014 Aug 14
2
[LLVMdev] Alias Analysis Semantics
On Thu, Aug 14, 2014 at 6:37 AM, Daniel Berlin <dberlin at dberlin.org> wrote: > On Wed, Aug 13, 2014 at 8:35 PM, Jeremy Salwen <jeremysalwen at gmail.com> wrote: >> Hey Daniel, >> >> Thanks again for the help. I'm still a bit confused about the interface to >> the alias analysis. It seems like we are talking about different >> interfaces. >
2014 Aug 21
2
[LLVMdev] Alias Analysis Semantics
...gt; > std::vector<int> A(100); > > > > int* x,y; > > > > > > > > > > > > > > > > > > x_1=GEP A, 0, 0 > > > > > > > > for(int i=0; i<100; i++) { > > i_2 = phi (0, i_3) > > x_2 = phi(x_1, x_3) > > y_1 = GEP A, 0, i_2 > > temp = load x_2 > > store y_1, temp > > temp2 = add i_2, 1 > > x_3 = GEP A, 0, temp2 > > i_3 = add i_2, 1 > > } > > > > > > As you can see, every time you redefine the value of the pointer x to > > a new...
2009 Feb 12
1
General query regarding scoring new observations
Hi, I was wondering if I can have some advice on the following problem. Let's say that I have a problem in which I want to predict a binary outcome and I use logistic regression for that purpose. In addition, suppose that my model includes predictors that will not be used in scoring new observations but must be used during model training to absorb certain effects that could bias the
2014 Aug 13
2
[LLVMdev] Alias Analysis Semantics
Thanks Daniel! I think you've cleared up some of my misconceptions, but I still am a bit confused about some of the corner cases. Suppose we had something like this std::vector<int> A(100); > int* x,y; > x=&A[0]; > for(int i=0; i<100; i++) { > y=&A[i]; > *y=*x; > x=&A[i+1]; > } > Would the load and store instructions be MustAlias? I
2009 Aug 24
2
Formulas in gam function of mgcv package
Dear R-experts, I have a question on the formulas used in the gam function of the mgcv package. I am trying to understand the relationships between: y~s(x1)+s(x2)+s(x3)+s(x4) and y~s(x1,x2,x3,x4) Does the latter contain the former? what about the smoothers of all interaction terms? I have (tried to) read the manual pages of gam, formula.gam, smooth.terms, linear.functional.terms but
2009 Aug 24
2
Formulas in gam function of mgcv package
Dear R-experts, I have a question on the formulas used in the gam function of the mgcv package. I am trying to understand the relationships between: y~s(x1)+s(x2)+s(x3)+s(x4) and y~s(x1,x2,x3,x4) Does the latter contain the former? what about the smoothers of all interaction terms? I have (tried to) read the manual pages of gam, formula.gam, smooth.terms, linear.functional.terms but
2017 Nov 05
5
Extreme bunching of random values from runif with Mersenne-Twister seed
On 04/11/2017 10:20 PM, Daniel Nordlund wrote: > Tirthankar, > > "random number generators" do not produce random numbers. Any given > generator produces a fixed sequence of numbers that appear to meet > various tests of randomness. By picking a seed you enter that sequence > in a particular place and subsequent numbers in the sequence appear to > be unrelated.
2024 Feb 23
0
Data consideration in executing pca
Dear R users, I have a txt file named 'data_1.txt' whose first column contains the names of the individuals and the other columns contain the values of four variables X_1,X_2,X_3 and X_4. I read it with R from its location and called it data. I'd like to do a normalized principal component analysis. I started by calculating the correlation matrix: cor(data) I got the following message: Error in cor(nnotes) : 'x' must be numeric. I eliminated the first column of...
2007 Jun 28
0
Evaluating predictive power with no intercept-statistics question - not R question
I realize that the following has been talked about on this list many times before in some related way but I am going to ask for help anyway because I still don't know what to do. Suppose I have no intercept models such as the following : Y = B*X_1 + error Y = B*X_2 + error Y = B*X_3 + error Y = B*X_4 + error and I run regressions on each ( over the same sample of Y ) and now I want to evaluate which X has the greatest predictive power. I'm fairly certain that R squared is not applicable because of the lack of an intercept but I was wondering what was ? Any references to...
2007 Nov 19
2
All nonnegative integer solution
Dear all, Is there any method in R to find all possible nonnegative integer solutions to the linear equation with unit coefficients as follow: X1+X2+...+Xk=N Thank you, Amin Zollanvari
2007 Aug 15
1
Polynomial fitting
Hi everybody! I'm looking some way to do in R a polynomial fit, say like polyfit function of Octave/MATLAB. For who don't know, c = polyfit(x,y,m) finds the coefficients of a polynomial p(x) of degree m that fits the data, p(x[i]) to y[i], in a least squares sense. The result c is a vector of length m+1 containing the polynomial coefficients in descending powers: p(x) = c[1]*x^n +
2017 Nov 05
0
Extreme bunching of random values from runif with Mersenne-Twister seed
...ess is aware of the function output. I would say that it must be, and he should be investigating how that happens if he is worried about the output, he shouldn't be worrying about R's RNG. > Hmm, no. The basic issue is that RNGs are constructed so that with x_{n+1} = f(x_n), x_1, x_2, x_3,... will look random, not so that f(s_1), f(s_2), f(s_3), ... will look random for any s_1, s_2, ... . This is true, even if seeds s_1, s_2, ... are not chosen so as to mess with the RNG. In the present case, it seems that the seeds around 86e6 tend to give similar output. On the other hand, it is...