AI-GEOSTATS: Re: Kriging using Nugget Model

2007-01-03 Thread bob sandefur
Before I Kriged with a pure nugget variogram I would ask: 1. How many data points? 2. Do you expect the data to be spatially uncorrelated? (i.e. whatÂ’s that variable?) 3. If you transform distribution to approximate normal is variogram still pure nugget? 4. Does regression o

AI-GEOSTATS: Re: Kriging using Nugget Model

2007-01-03 Thread Isobel Clark
Mehari SURFER will be giving you the arithmetic mean of the samples which fall inside your search radius, not all possible samples. Effectively, you are getting a "moving average". Isobel http://www.kriging.com

RE: AI-GEOSTATS: Re: Kriging using Nugget Model

2007-01-03 Thread Zhang, Chaosheng
TED] [mailto:[EMAIL PROTECTED] On Behalf Of Edzer J. Pebesma Sent: 02 January 2007 16:28 To: Isobel Clark Cc: Mehari Tekeste; ai-geostats@jrc.it Subject: Re: AI-GEOSTATS: Re: Kriging using Nugget Model For block kriging yes, for point kriging the prediction (standard) error will be close to sigm

Re: AI-GEOSTATS: Re: Kriging using Nugget Model

2007-01-03 Thread Edzer J. Pebesma
il: [EMAIL PROTECTED] Web: http://www.nuigalway.ie/geography/gis -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Edzer J. Pebesma Sent: 02 January 2007 16:28 To: Isobel Clark Cc: Mehari Tekeste; ai-geostats@jrc.it Subject: Re: AI-GEOSTATS: Re: Kriging using Nugg

Re: AI-GEOSTATS: Re: Kriging using Nugget Model

2007-01-02 Thread Edzer J. Pebesma
For block kriging yes, for point kriging the prediction (standard) error will be close to sigma. And happy new year to everyone on ai-geostats! -- Edzer Isobel Clark wrote: Mehari If you use a semi-variogram which is just nugget, the kriging estimate will be the arithmetic mean of the sampl

AI-GEOSTATS: Re: Kriging using Nugget Model

2007-01-02 Thread Isobel Clark
Mehari If you use a semi-variogram which is just nugget, the kriging estimate will be the arithmetic mean of the sample values and the standard error will be the standard sigma/root n of classical statistics. Isobel Mehari Tekeste <[EMAIL PROTECTED]> wrote: Can I get some suggestio