search for: equations

Displaying 20 results from an estimated 2606 matches for "equations".

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2010 Jul 26
2
easy debugging
I am new to R. Used to use FORTRAN. R is so different from FORTRAN. The following codes would work in FOTRAN. I am trying to put an upper limit at 120. If the score is > 120, it is assigned 120. Or else, keep the original values. version 1: equated<-11 result<-11 equated<-c(111.0,112.06, 112.9, 113.8, 115.0, 116.2, 117.0, 118.0, 120.5, 120.5, 120.5) for (i in 1:11){ if (equated >
2012 Mar 22
1
Simalteneous Equation Doubt in R
...on: St= a0+a1Pt-1+a2Rt-1+a3St-1+a5D1+a6D2+a7D3+U1 -(1) Where D1,D2,D3=Quarterly Dummy Variables(Since quarterly data are considered) Here, Supply equation has 1 endogenous (St) & 6 exogenous variables (P t-1,Rt-1,St-1,D1,D2,D3) Demand Side: Demand of corn is divided into 3 equations: Feed equation: Ft=b0+b1Pt+b2P(sm)t+b3Bt+b4COFt+b5Ht+a6D1+a7D2+a8D3+U2 -(2) here there are 2 endogenous variable(Ft, Pt) & 7 exogenous variables (P(sm)t,Bt,COFt,D1,D2,D3) Export equation: EXt= c0+c1Pt+c2EXt-1+c3Wt+c4DXt+c5GDPt+c6D1+c7D2+c8D3+U3 -(3) here there are 2 endogeno...
2017 Jul 13
2
Question on Simultaneous Equations & Forecasting
Frances, I would not advise Gauss-Seidel for non linear models. Can be quite tricky, slow and diverge. You can write your model as a non linear system of equations and use one of the nonlinear solvers. See the section "Root Finding" in the task view NumericalMathematics suggesting three packages (BB, nleqslv and ktsolve). These package are certainly able to handle medium sized models. (https://cran.r-project.org/web/views/NumericalMathematics.html)...
2017 Jul 12
2
Question on Simultaneous Equations & Forecasting
Hello, I have estimated a simultaneous equation model (similar to Klein's model) in R using the system.fit package. I have an identity equation, along with three other equations. Do you know how to explicitly identify the identity equation in R? I am also trying to forecast the dependent variables in the simultaneous equation model, while incorporating the identity equation in the forecasts. Is there a way to do this in R? The only way that I have been able to forecast t...
2010 Oct 01
3
maximum likelihood problem
I am trying to figure out how to run maximum likelihood in R. Here is my situation: I have the following equation: equation<-(1/LR-(exp(-k*T)*LM)*(1-exp(-k))) LR, T, and LM are vectors of data. I want to R to change the value of k to maximize the value of equation. My attempts at optim and optimize have been unsuccessful. Are these the recommended functions that I should use to maximize
2017 Jul 13
0
Question on Simultaneous Equations & Forecasting
...functions of the Cobb-Douglas type. Best, Bernhard -----Urspr?ngliche Nachricht----- Von: Berend Hasselman [mailto:bhh at xs4all.nl] Gesendet: Donnerstag, 13. Juli 2017 10:53 An: OseiBonsu, Frances Cc: Pfaff, Bernhard Dr.; r-help at r-project.org Betreff: [EXT] Re: [R] Question on Simultaneous Equations & Forecasting Frances, I would not advise Gauss-Seidel for non linear models. Can be quite tricky, slow and diverge. You can write your model as a non linear system of equations and use one of the nonlinear solvers. See the section "Root Finding" in the task view NumericalMathemati...
2003 Apr 21
4
nonlinear equation solver?
Dear R-Help, I am trying to use R to solve a nonlinear equation many times for different values. I am looking for a mathematical nonlinear equation solution which may not have a closed solution form. For example, I have equation: 2 = (t^2)/log(t) What is t? I am wondering how to solve it in R. Many thanks, Zhu Wang Statistical Science Department SMU.
2017 Jul 13
0
Question on Simultaneous Equations & Forecasting
...ample endogenous variables, i.e., you are assessing the stability of your model. Because forecast-errors cumulate over time in a dynamic ex-post forecast, this is a rather good and stringent model-test. Incidentally, when you use simultaneous equation models on a larger scale (say, between 200-300 equations, like medium-sized macroeconomic models), the only route to go for, is by estimating your reaction equations separately and then putting all your pieces - including identities and/or technical equations - together in a format suitable for applying the Gauss-Seidel method. Hence, forget about 2SLS o...
2011 Feb 22
1
System of related regression equations
Dear all, I would like to estimate a system of regression equations of the following form: y1 = a1 + b1 x1 + b2x2 + e1 y2 = a2 + c1 y1 + c2 x2 + c3 x3 + e2 Specifically the dependent variable in Equation 1 appears as an independent variable in Equation 2. Additionally some independent variables that appear in Equation 1 are also included in Equation 2. I assume...
2005 Nov 30
8
Solving Systems of Non-linear equations
I am trying to write a function that will solve a simple system of nonlinear equations for the parameters that describe the beta distribution (a,b) given the mean and variance. mean = a/(a+b) variance = (a*b)/(((a+b)^2) * (a+b+1)) Any help as to where to start would be welcome. -- Scott Story Graduate Student MSU Ecology Department 319 Lewis Hall Bozeman, Mt 59717 406.994.267...
2017 Jul 13
1
Question on Simultaneous Equations & Forecasting
...est, > Bernhard > > -----Urspr?ngliche Nachricht----- > Von: Berend Hasselman [mailto:bhh at xs4all.nl] > Gesendet: Donnerstag, 13. Juli 2017 10:53 > An: OseiBonsu, Frances > Cc: Pfaff, Bernhard Dr.; r-help at r-project.org > Betreff: [EXT] Re: [R] Question on Simultaneous Equations & Forecasting > > Frances, > > I would not advise Gauss-Seidel for non linear models. Can be quite tricky, slow and diverge. > > You can write your model as a non linear system of equations and use one of the nonlinear solvers. > See the section "Root Finding"...
2006 Jun 16
6
rendering mathematical equations
Any recommendations on how I can get mathematical equations into my resulting html? (Besides using x^2^ type markup.) I figure I could parse out equation text from my main text before RedCloth ever sees it... and then maybe create png''s somehow from it, putting the links to them back into the main text before handing it over to RC. But I don'&...
2009 Aug 13
3
Solutions of equation systems
Hello all! Maybe it's a newbie question(in fact I _am_, a newbie), but I hope you'll find the solution. I have an equation system which has k equation and n variables (k<n). I would like to obtain a description of the solutions (which can be the equation of lines or a plane, or everything else) with the lesser degree of freedom, obviously using R. In other words, I would like to
2011 Nov 15
1
Estimating model parameters for system of equations
Hi all, I'm trying to estimate model parameters in R for a pretty simple system of equations, but I'm having trouble. Here is the system of equations (all derivatives): eqAlgae <- (u_Amax * C_A) * (1 - (Q_Amin / Q_A)) eqQuota <- (p_max * R_V) / (K_p + R_V) - ((Q_A-Q_Amin)*u_Amax) eqResource <- -C_A * (p_max * R_V) / (K_p + R_V) eqSystem <- list(C_A = eqAlgae, Q_A = eqQuota...
2011 Nov 04
2
Equations in Word 2007
Greetings, gentlemen. When I open a doc-file with some formulas (the file was created on windows machine), sometimes they are rendered a bit wrong. After opening them in equation editor they are rendered OK. After saving the doc-file anything is OK. But when the changed file is opened on MS Word 2007 on Windows machine, the formulas which were opened in Equation Editor on wine Word, are rendered
2010 Apr 26
1
finite difference scheme for 2D differential equations
Hello everyone, I am trying to solve 2D differential equations using finite difference scheme in R. I have been able to work with the equations with only one spatial dimensions but I want to extend it to the two dimensional problem. For example i can simulate one dimensional diffusion using a code like the following. But I want to write a similar code for,say,...
2008 Nov 21
1
equation of a line or curve
Hi R users I used the function line(x,y) and line(lowess(x,y)) to see the correlation between 2 variables (x,y). Here is my question: is there a way to ask R to tell me the equation of -this line : line(x,y) -this curve: line(lowess(x,y)) Best regards -- View this message in context: http://www.nabble.com/equation-of-a-line-or-curve-tp20628845p20628845.html Sent from the R help mailing list
2010 Jan 05
4
solving cubic/quartic equations non-iteratively
To R-helpers, R offers the polyroot function for solving mentioned equations iteratively. However, Dr Math and Mathworld (and other places) show in detail how to solve mentioned equations non-iteratively. Do implementations for R that are non-iterative and that solve mentioned equations exists? Regards, Mads Jeppe
2010 Mar 04
2
which coefficients for a gam(mgcv) model equation?
Dear users, I am trying to show the equation (including coefficients from the model estimates) for a gam model but do not understand how to. Slide 7 from one of the authors presentations (gam-theory.pdf URL: http://people.bath.ac.uk/sw283/mgcv/) shows a general equation log{E(yi )} = ?+ ?xi + f (zi ) . What I would like to do is put my model coefficients and present the equation used. I am an
2010 Jan 21
1
Displaying Equation With Numerator and Demomenator On A Plot...
...te the equation in Latex, but wasn't sure if this format would translate to plotting. \begin{equation} ? x = \frac{b +/- sqrt(b^2 - 4*a*c)}{2*a} \end{equation} ? My searched turned up the following: http://tolstoy.newcastle.edu.au/R/e6/help/09/03/9010.html ? Unfortunately, it does not address equations with numerators and demomenators.? ? Here is a guess (but this fails): ? ### Change spacing to allow for multiline title par(oma=c(2, 0, 4, 0)) ### Some greek letters mu <- 0 alpha <- 1 beta <- 2 delta <- 3 lambda <- 4 ### Some graph or other plot(1:10,1:10) mtext(expression(bold(&q...