Mathematica 9 is now available
Services & Resources / Wolfram Forums
-----
 /
MathGroup Archive
1998
*January
*February
*March
*April
*May
*June
*July
*August
*September
*October
*November
*December
*Archive Index
*Ask about this page
*Print this page
*Give us feedback
*Sign up for the Wolfram Insider

MathGroup Archive 1998

[Date Index] [Thread Index] [Author Index]

Search the Archive

Re: problem with Needs[ ] command

  • To: mathgroup at smc.vnet.net
  • Subject: [mg13583] Re: problem with Needs[ ] command
  • From: "Allan Hayes" <hay at haystack.demon.cc.uk>
  • Date: Mon, 3 Aug 1998 03:53:44 -0400
  • References: <6pu7vl$fmo$6@dragonfly.wolfram.com>
  • Sender: owner-wri-mathgroup at wolfram.com

Jordan:
The problem is that an input line is parsed before being evaluated. In
this case
Needs["Statistics`LinearRegression`"]; reg = Regress[data, {1, a}, a];
is taken as one inputline and Regress is created as Global`Regress
before Needs is evaluated (which creates
Statistics`LinearRegression`Regress and issues the warning message];

There seem to be be two ways out:
1) make sure that
    Needs["Statistics`LinearRegression`"] is one input line followed by
another input line
    reg = Regress[data, {1, a}, a]

For example

data = {{12,1},{7,2},{8,3},{5,4},{3,5}};
Needs["Statistics`LinearRegression`"]; reg = Regress[data, {1, a}, a];
Chop[reg, 10^-3]

For safety put the second and third lines in distinct cells.

2) us the long name, including context for Regress; thus ( I put all the
inside A[..] to make it explicit that all is in one input line).

A[data = {{12,1},{7,2},{8,3},{5,4},{3,5}};
Needs["Statistics`LinearRegression`"]; reg =
Statistics`LinearRegression`Regress[data, {1, a}, a]; Chop[reg, 10^-3]
]


Allan

------------------------------------------------------------- 
Allan Hayes
Training and Consulting
Leicester UK
http://www.haystack.demon.co.uk
hay at haystack.demon.co.uk
voice: +44 (0)116 271 4198
fax: +44(0)116 271 8642

Jordan Milev wrote in message <6pu7vl$fmo$6 at dragonfly.wolfram.com>...
>Hello!  Here's what I have:  In a new notebook type in the following:
>
>data = {{12,1},{7,2},{8,3},{5,4},{3,5}};
>Needs["Statistics`LinearRegression`"]; reg = Regress[data, {1, a}, a];
>Chop[reg, 10^-3]
>
>Here's what I get:
>
>Regress::"shdw":
>    "Symbol \!\(\"Regress\"\) appears in multiple contexts \
>\!\({\"Statistics`LinearRegression`\", \"Global`\"}\); definitions in
>context \
>\!\(\"Statistics`LinearRegression`\"\) may shadow or be shadowed by
>other \ definitions."
>
>Regress[{{12,1},{7,2},{8,3},{5,4},{3,5}},{1,a},a]
>
>Why does Mathematica display the error?
>
>Jordan
>
>
>
>



  • Prev by Date: Using $PreRead with Notebook frontend
  • Next by Date: Re: ScaledMultipleListPlot
  • Previous by thread: Using $PreRead with Notebook frontend
  • Next by thread: Re: ScaledMultipleListPlot