Thursday 22 August 2019

GCDkit 6.0 has been unleashed. What is new?

On August 16, 2019 has been released a new version of GCDkit 6.0. It was developed in R 3.6.0 and code-named Il padrino sono io. This is the first truly platform independent version that could run on all systems, including Mac OS X and Linux from both command line and graphical user interface (GUI). The most important changes are summarised below.

Platform-independent GUI
  • Optional platform-independent Tcl/Tk graphical user interface (GUI)
  • In both command-line/batch mode and from graphical user interface (GUI), the GCDkit should run also operation systems other than Windows, notably Linux or Mac OSX. To start GUI on non-Windows systems, type menuet()

Performance improvements
  • Quicker response of the menu for geotectonic plots that is newly being built only once, upon the system startup 
  • Quicker and improved routine enabling overplotting datasets, especially values after Debon and Le Fort.
  • Some norms (most notably CIPW) were speeded up considerably.

User-defined plots

  •  Help pages to user-defined plots are added automatically to the html help system.
Bug fixes
  • Correct function on the Chinese (and perhaps other non-European) locales.
New plugins
  • New plugin for ternary projection from biotite (Moyen et al. 2017).
New geotectonic/general purpose diagrams
  • B vs. Mg/(Fe + Mg), Q vs. B, K/(Na+K) vs. B and BQF ternary diagram of Debon and Le Fort (1983, 1988) 
  • Diagrams for classification of feldspathic igneous rocks of Frost and Frost (2008)
  • Diagram of Laurent et al. (2014) to decipher possible source of granitic magmas
  • New function phasePropPlot() that plots barplot of mineral proportions
  • Mesonormative Q'-ANOR diagram of Streckeisen and Le Maitre (1976) was added to the Classification plots and can be indeed used for this purpose now. If necessary, a matrix of mesonormative values can be provided upon call; otherwise these are to be calculated anew. 

The new version of GCDkit has been unveiled at the Goldschmidt Conference in Barcelona on 21 August. Follow this link for the PDF version of the poster. 

Sunday 3 March 2019

GCDkit not starting on Chinese locales?

Several users from China have reported problems with running GCDkit 5.0.

The troublemaker is the newly introduced Eartchem module, as already mentioned here: 

The problem is clearly with multibyte encoding of Chinese characters. But the bug may be also affecting the users on other locales/systems, including Mac.

The fix is relatively simple, though. Please, in the line 216 of the EarthChemFUN.r file, replace the text by:

if(.Platform$OS.type=="windows") zzz[zzz==intToUtf8(0x00c2)]<-NA

and restart GCDkit.

Please accept my apologies. The next version of GCDkit (6.0), now at the stage of beta testing, will have this problem solved.


Special thanks go to Jiacheng Tian and Shi-Chao Li for their helpful bug reports and patience.

Plotting TAS diagram of Le Bas et al. (1986)

By far the most common bug report that we are getting concerns the implementation of the total alkali-silica (TAS) diagram of Le Bas et al. (1986) in GCDkit. But in reality, it is  not a bug, but a feature. One should be aware of the fact that the analyses plotted have been recalculated on 100% anhydrous (volatile-free) basis.  This is in accordance with the recommendation of the IUGS  Subcommission on the Systematics of Igneous Rocks (Le Bas et al. 1986; Le Maitre ed. 2002).

On the other hand, such a recalculation is not carried out for subsequent modifications of the TAS diagram (Cox et al. 2002; Middlemost 1994), where rough data are plotted.

In any case, using analyses with too high volatile contents is to be avoided, as they are suspicious from being affected by alteration and attendant mobility of alkalis.   

Cox KG, Bell JD & Pankhurst (1979) The Interpretation of Igneous Rocks.
Allen & Unwin, London

Le Bas MJ, Le Maitre RW, Streckeisen A & Zanettin B (1986)
A chemical classification of volcanic rocks based on the total alkali-silica
diagram. J Petrology 27: 745-750

Le Maitre RW (ed) (2002) Igneous rocks: a classification and glossary of terms: recommendations
of the International Union of Geological Sciences, Subcommission on the Systematics of
Igneous Rocks, 2nd edition. Cambridge University Press

Middlemost EAK (1994) Naming materials in the magma/igneous rock system.
Earth Sci Rev 37: 215-224