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	<title>Comments on: Correlation scatter-plot matrix for ordered-categorical data</title>
	<atom:link href="http://www.r-statistics.com/2010/04/correlation-scatter-plot-matrix-for-ordered-categorical-data/feed/" rel="self" type="application/rss+xml" />
	<link>http://www.r-statistics.com/2010/04/correlation-scatter-plot-matrix-for-ordered-categorical-data/</link>
	<description>Writing about statistics with R, and open source stuff (software, data, community)</description>
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	<item>
		<title>By: Benjamin</title>
		<link>http://www.r-statistics.com/2010/04/correlation-scatter-plot-matrix-for-ordered-categorical-data/comment-page-1/#comment-3162</link>
		<dc:creator>Benjamin</dc:creator>
		<pubDate>Fri, 27 Aug 2010 12:27:45 +0000</pubDate>
		<guid isPermaLink="false">http://www.r-statistics.com/?p=256#comment-3162</guid>
		<description>Hey Tal,

the graph looks great! Im new to R and I do have some problems to get the Syntax work. Could you help me? I&#039;ve got a data frame for which I need all corrrelations in a scatter plot (23 Variables, I know its a lot).  The data is ordinal with 4 scale steps (1 to 4). Can I read in the wholde dataset or should I list all the variable names in? I deleted all other Variables in the dataset, so there are only the 23 Variables with no missings.
Thanks a lot!</description>
		<content:encoded><![CDATA[<p>Hey Tal,</p>
<p>the graph looks great! Im new to R and I do have some problems to get the Syntax work. Could you help me? I&#8217;ve got a data frame for which I need all corrrelations in a scatter plot (23 Variables, I know its a lot).  The data is ordinal with 4 scale steps (1 to 4). Can I read in the wholde dataset or should I list all the variable names in? I deleted all other Variables in the dataset, so there are only the 23 Variables with no missings.<br />
Thanks a lot!</p>
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	</item>
	<item>
		<title>By: Tal Galili</title>
		<link>http://www.r-statistics.com/2010/04/correlation-scatter-plot-matrix-for-ordered-categorical-data/comment-page-1/#comment-2910</link>
		<dc:creator>Tal Galili</dc:creator>
		<pubDate>Mon, 12 Jul 2010 15:50:22 +0000</pubDate>
		<guid isPermaLink="false">http://www.r-statistics.com/?p=256#comment-2910</guid>
		<description>Thank you John, I won&#039;t get to fixing it before I come back from useR 2010.

If any reader wishes to offer a fix - I&#039;d be glad to incorporate it.</description>
		<content:encoded><![CDATA[<p>Thank you John, I won&#8217;t get to fixing it before I come back from useR 2010.</p>
<p>If any reader wishes to offer a fix &#8211; I&#8217;d be glad to incorporate it.</p>
]]></content:encoded>
	</item>
	<item>
		<title>By: John</title>
		<link>http://www.r-statistics.com/2010/04/correlation-scatter-plot-matrix-for-ordered-categorical-data/comment-page-1/#comment-2888</link>
		<dc:creator>John</dc:creator>
		<pubDate>Thu, 08 Jul 2010 04:33:24 +0000</pubDate>
		<guid isPermaLink="false">http://www.r-statistics.com/?p=256#comment-2888</guid>
		<description>Your function renders text size of negative r values incorrectly, because size is based on string width, which is longer for negative numbers (5 characters) than for positive numbers (4 characters). 
You can see this effect in your screenshot above, where -0.73 is in slightly smaller text than is 0.70. 
The original function over at R Graph Gallery didn&#039;t run into this problem because it displayed abs(r).</description>
		<content:encoded><![CDATA[<p>Your function renders text size of negative r values incorrectly, because size is based on string width, which is longer for negative numbers (5 characters) than for positive numbers (4 characters).<br />
You can see this effect in your screenshot above, where -0.73 is in slightly smaller text than is 0.70.<br />
The original function over at R Graph Gallery didn&#8217;t run into this problem because it displayed abs(r).</p>
]]></content:encoded>
	</item>
	<item>
		<title>By: Tal Galili</title>
		<link>http://www.r-statistics.com/2010/04/correlation-scatter-plot-matrix-for-ordered-categorical-data/comment-page-1/#comment-2843</link>
		<dc:creator>Tal Galili</dc:creator>
		<pubDate>Fri, 02 Jul 2010 20:07:24 +0000</pubDate>
		<guid isPermaLink="false">http://www.r-statistics.com/?p=256#comment-2843</guid>
		<description>Hi Mahtab,
Glad to have helped :)

In such a case, I would suggest:
1) using bootstrap/permutation methods in order to calculate the P values.
2) Checking what methods exists for this case in the literature and see if they&#039;ve got an R implementation.


Cheers, 
Tal</description>
		<content:encoded><![CDATA[<p>Hi Mahtab,<br />
Glad to have helped <img src='http://www.r-statistics.com/wp-includes/images/smilies/icon_smile.gif' alt=':)' class='wp-smiley' /> </p>
<p>In such a case, I would suggest:<br />
1) using bootstrap/permutation methods in order to calculate the P values.<br />
2) Checking what methods exists for this case in the literature and see if they&#8217;ve got an R implementation.</p>
<p>Cheers,<br />
Tal</p>
]]></content:encoded>
	</item>
	<item>
		<title>By: Mahtab Gh</title>
		<link>http://www.r-statistics.com/2010/04/correlation-scatter-plot-matrix-for-ordered-categorical-data/comment-page-1/#comment-2842</link>
		<dc:creator>Mahtab Gh</dc:creator>
		<pubDate>Fri, 02 Jul 2010 20:04:13 +0000</pubDate>
		<guid isPermaLink="false">http://www.r-statistics.com/?p=256#comment-2842</guid>
		<description>Hi,

First of all, thanks for putting together the code for Likert-scale correlation matrix; it has helped me a lot.

My question is about the use of Spearman&#039;s rho: as you know, Spearman&#039;s formula cannot calculate p-values with good precision, when there are ties in the ranks.  Such ties usually exist in survey data.  Do you suggest using Pearson&#039;s corr. coeff. instead?

I&#039;d really appreciate if you could comment on this.</description>
		<content:encoded><![CDATA[<p>Hi,</p>
<p>First of all, thanks for putting together the code for Likert-scale correlation matrix; it has helped me a lot.</p>
<p>My question is about the use of Spearman&#8217;s rho: as you know, Spearman&#8217;s formula cannot calculate p-values with good precision, when there are ties in the ranks.  Such ties usually exist in survey data.  Do you suggest using Pearson&#8217;s corr. coeff. instead?</p>
<p>I&#8217;d really appreciate if you could comment on this.</p>
]]></content:encoded>
	</item>
	<item>
		<title>By: EcoArte &#187; El “arte”del análisis de datos: De las hojas de cálculo a R &#8211; Juan Freire</title>
		<link>http://www.r-statistics.com/2010/04/correlation-scatter-plot-matrix-for-ordered-categorical-data/comment-page-1/#comment-2614</link>
		<dc:creator>EcoArte &#187; El “arte”del análisis de datos: De las hojas de cálculo a R &#8211; Juan Freire</dc:creator>
		<pubDate>Sun, 09 May 2010 14:01:38 +0000</pubDate>
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		<title>By: EcoArte &#187; El “arte”del análisis de datos: De las hojas de cálculo a R Juan Freire Universidade da Coruña</title>
		<link>http://www.r-statistics.com/2010/04/correlation-scatter-plot-matrix-for-ordered-categorical-data/comment-page-1/#comment-2613</link>
		<dc:creator>EcoArte &#187; El “arte”del análisis de datos: De las hojas de cálculo a R Juan Freire Universidade da Coruña</dc:creator>
		<pubDate>Sun, 09 May 2010 13:48:25 +0000</pubDate>
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	<item>
		<title>By: Tal Galili</title>
		<link>http://www.r-statistics.com/2010/04/correlation-scatter-plot-matrix-for-ordered-categorical-data/comment-page-1/#comment-2471</link>
		<dc:creator>Tal Galili</dc:creator>
		<pubDate>Sat, 10 Apr 2010 16:19:15 +0000</pubDate>
		<guid isPermaLink="false">http://www.r-statistics.com/?p=256#comment-2471</guid>
		<description>Thanks Ian for the positive feedback :)

Also thanks for pointing that the graphic doesn&#039;t use solution 2 (I&#039;ll correct that in the article).  

The reason I wrote it is that the code give an hidden option to use solution 2 (I just didn&#039;t feel it added enough in this case to include it).

For people who will want to implement solution 2, please remove the &quot;note #&quot; sign from:
   #the.col &lt;- heat_hcl(length(x))[z]
And
	inches=F, bg= &quot;grey&quot;,#the.col ,
In the:
panel.smooth.ordered.categorical  function.

I am sure it could be improved more.  My biggest problem (with both the colors and the sizes), is how to make sure they scale &quot;well&quot; for various situations in the data.
If you have any thoughts - be welcomed to share them!

Cheers :)
Tal</description>
		<content:encoded><![CDATA[<p>Thanks Ian for the positive feedback <img src='http://www.r-statistics.com/wp-includes/images/smilies/icon_smile.gif' alt=':)' class='wp-smiley' /> </p>
<p>Also thanks for pointing that the graphic doesn&#8217;t use solution 2 (I&#8217;ll correct that in the article).  </p>
<p>The reason I wrote it is that the code give an hidden option to use solution 2 (I just didn&#8217;t feel it added enough in this case to include it).</p>
<p>For people who will want to implement solution 2, please remove the &#8220;note #&#8221; sign from:<br />
   #the.col < - heat_hcl(length(x))[z]<br />
And<br />
	inches=F, bg= &#8220;grey&#8221;,#the.col ,<br />
In the:<br />
panel.smooth.ordered.categorical  function.</p>
<p>I am sure it could be improved more.  My biggest problem (with both the colors and the sizes), is how to make sure they scale &#8220;well&#8221; for various situations in the data.<br />
If you have any thoughts &#8211; be welcomed to share them!</p>
<p>Cheers <img src='http://www.r-statistics.com/wp-includes/images/smilies/icon_smile.gif' alt=':)' class='wp-smiley' /><br />
Tal</p>
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	<item>
		<title>By: Ian Fiske</title>
		<link>http://www.r-statistics.com/2010/04/correlation-scatter-plot-matrix-for-ordered-categorical-data/comment-page-1/#comment-2470</link>
		<dc:creator>Ian Fiske</dc:creator>
		<pubDate>Sat, 10 Apr 2010 15:55:20 +0000</pubDate>
		<guid isPermaLink="false">http://www.r-statistics.com/?p=256#comment-2470</guid>
		<description>Thanks!  That&#039;s a great plot for assessing correlation of ordinal variables.

Small typo: the graphic uses solutions 3-4, not 2-4 as the dots have no color gradient.</description>
		<content:encoded><![CDATA[<p>Thanks!  That&#8217;s a great plot for assessing correlation of ordinal variables.</p>
<p>Small typo: the graphic uses solutions 3-4, not 2-4 as the dots have no color gradient.</p>
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