[R] Printing a list of simultaneous equations

[Michael Friendly]

John-

Don't try to forge a new wheel, when you can get one ready made
and it might fit your wagon.

Check out the `matlib` package on CRAN and devel on github: 
https://github.com/friendly/matlib

install.packages("matlib")
library(matlib)
A <- matrix(c(1,2,3, -1, 2, 1), 3, 2)
b <- c(2,1,3)
showEqn(A, b)

 > showEqn(A, b)
1*x1 - 1*x2  =  2
2*x1 + 2*x2  =  1
3*x1 + 1*x2  =  3
 >
sound like what you want.  Various vignettes illustrate this, also 
showing how to plot linear equations in 2D, 3D.

browseVignettes("matlib")


On 1/18/2019 7:02 AM, Sorkin, John wrote:
> I am trying to print a list of equations in an easily readable form. At this time all I can get is  a series of characters enclosed in quotation marks rather than equations with numbers and equal signs. What I get is
> 
> 
>      y     equalsigns x   z
> eq1 "0.5" "="        "1" "2"
> eq2 "4"   "="        "2" "3"
> 
> 
> When what I want is
> 
>            y         x   z
> 
> eq1  0.5  =  1   2
> eq2  4.0  =  2   3
> 
> 
> I am enclosing my R code below:
> 
> # Create matrix of  coefficients of independent variables.
> a  <- matrix(c(1,2,2,3),nrow=c(2,2),byrow=TRUE)
> dimnames(a)<-list(c("eq1","eq2"),c("x","z"))
> cat("Matrix of independent variables\n")
> a
> 
> # Create vector of dependent variables.
> b <- matrix(c(0.5,4.0),nrow=c(2,1))
> 
> dimnames(b)<-list(c("eq1","eq2"),c("y"))
> cat("Vector of dependent variables","\n")
> b
> 
> cat("System of equations to be solved")
> equalsigns <- c("=","=")
> cbind(b,equalsigns,a)
> 
> 
> 
> 
> Thank you,
> 
> John
> 
> 
> 
> 
> 
> John David Sorkin M.D., Ph.D.
> Professor of Medicine
> Chief, Biostatistics and Informatics
> University of Maryland School of Medicine Division of Gerontology and Geriatric Medicine
> Baltimore VA Medical Center
> 10 North Greene Street
> GRECC (BT/18/GR)
> Baltimore, MD 21201-1524
> (Phone) 410-605-7119
> (Fax) 410-605-7913 (Please call phone number above prior to faxing)
> 
> 
> 	[[alternative HTML version deleted]]
> 


-- 
Michael Friendly     Email: friendly AT yorku DOT ca
Professor, Psychology Dept. & Chair, ASA Statistical Graphics Section
York University      Voice: 416 736-2100 x66249 Fax: 416 736-5814
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