Mapping-data analyzing method and apparatus

• US 20060088217A1
• Filed: 10/24/2005
• Published: 04/27/2006
• Est. Priority Date: 10/25/2004
• Status: Active Grant

• Current Assignee: Jasco Corporation
• Original Assignee: Jasco Corporation
• Inventors: Nagoshi, Toshiyuki, Akoa, Kenichi
• Granted Patent: US 7,515,769 B2
• Time in Patent Office: Days
• US Class Current: 382/191
• CPC Class Codes: G06F 18/40 Software arrangements specially adapted for pattern recognition, e.g. user interfaces or toolboxes therefor
• CPC Class Codes: G06V 20/695 Preprocessing, e.g. image segmentation

Abstract

It is an object of the present invention to provide a mapping-data analyzing method that can display a map in which sufficient information is extracted from the spectra of obtained mapping data to enable objective analysis. The mapping-data analyzing method of the present invention is used for analyzing mapping data obtained by measuring, with a spectrometer apparatus, spectra at a plurality of points on a specimen surface. The method comprises a principal-component calculating step and a grouped-map display step. In the principal-component calculating step, spectral data obtained at each point on the specimen surface is defined as an individual sample and principal component analysis, in which values at a plurality of wave numbers of each spectral data set serve as variables, is performed to calculate the scores of a plurality of principal components for each individual sample. In the grouped-map display step, the points on the specimen surface are divided into a plurality of groups based on the scores of a plurality of principal components calculated in the principal-component calculating step and a two-dimensional or three-dimensional map indicating to which group each point on the specimen surface belongs is displayed on a display device.

Claims

1. A mapping-data analyzing method for analyzing mapping data obtained by measuring, with a spectrometer apparatus, spectra at a plurality of points on a specimen surface, comprising:

a principal-component calculating step of defining at least part of spectral data obtained at each point on the specimen surface as an individual sample and performing principal component analysis, in which values at a plurality of wave numbers of each spectral data set serve as variables, to calculate the scores of a plurality of principal components for each individual sample; and

a grouped-map display step of dividing the points on the specimen surface into a plurality of groups based on the scores of a plurality of principal components calculated in the principal-component calculating step, and displaying on a display device a two-dimensional or three-dimensional map indicating to which group each point on the specimen surface belongs.

2. A mapping-data analyzing method according to claim 1, further comprising:

a scatterplot display step of displaying on the display device a two-dimensional or three-dimensional scatterplot of the individual samples, in which a plurality of principal components calculated in the principal-component calculating step define axes; and

a grouping setting step of setting grouping criteria in the grouped-map display step on the basis of the scatterplot displayed on the display device in the scatterplot display step.

3. A mapping-data analyzing method according to claim 1, further comprising:

a principal-component-score map display step of displaying on the display device a two-dimensional or three-dimensional map of the scores of a principal component calculated in the principal-component calculating step.

4. A mapping-data analyzing method according to claim 1, further comprising:

a similarity calculating step of calculating the similarity between the spectral data obtained at each point on the specimen surface and spectral data for one or a plurality of known substances, which is stored in a spectrum database.

5. A mapping-data analyzing method according to claim 4, wherein the similarity is a correlation coefficient or a Euclidean distance.

6. A mapping-data analyzing method according to claim 4, further comprising:

a step of displaying on the display device a two-dimensional or three-dimensional map of the similarity calculated in the similarity calculating step.

7. A mapping-data analyzing method according to claim 4, wherein the grouping performed in the grouped-map display step is carried out on the basis of the similarity.

8. A mapping-data analyzing method according to claim 1, further comprising:

a concentration calculating step of calculating the concentration of a predetermined substance present at each point on the specimen surface, from the spectral data obtained at each point on the specimen surface.

9. A mapping-data analyzing method according to claim 8, wherein the grouping performed in the grouped-map display step is carried out on the basis of the concentration calculated in the concentration calculating step.

10. A mapping-data analyzing method according to claim 8, further comprising:

a concentration-map display step of displaying a two-dimensional or three-dimensional map of the concentration calculated in the concentration calculating step.

11. A mapping-data analyzing method according to claim 1, further comprising:

a physical-property calculating step of calculating a physical-property at each point on the specimen surface, from the spectral data measured at each point on the specimen surface.

12. A mapping-data analyzing method according to claim 11, wherein the physical-property calculated in the physical-property calculating step is refractive index or dielectric constant.

13. A mapping-data analyzing method according to claim 11, wherein the grouping performed in the grouped-map display step is carried out on the basis of the physical-property calculated in the physical-property calculating step.

14. A mapping-data analyzing method according to claim 11, further comprising:

a physical-property-map display step of displaying on the display device a two-dimensional or three-dimensional map of the physical-property calculated in the physical-property calculating step.

15. A mapping-data analyzing method according to claim 1, further comprising:

a thickness calculating step of calculating a thickness at each point on the specimen surface, from the spectral data measured at each point on the specimen surface.

16. A mapping-data analyzing method according to claim 15, wherein the grouping performed in the grouped-map display step is carried out on the basis of the thickness at each point of the specimen, which is calculated in the thickness calculating step.

17. A mapping-data analyzing method according to claim 15, further comprising:

a thickness-map display step of displaying on the display device a two-dimensional or three-dimensional map of the thickness at each point on the specimen surface, which is calculated in the thickness calculating step.

18. A mapping-data analyzing program wherein each step in the mapping-data analyzing method according to claim 1 is executed on a computer.

19. A mapping-data analyzing apparatus for analyzing mapping data obtained by measuring, with a spectrometer apparatus, spectra at a plurality of points on a specimen surface, comprising:

a storage device for storing spectral data for each point on the specimen surface;

a principal-component calculating unit for defining at least part of the spectral data stored in the storage device as individual samples and performing principal component analysis, in which values at a plurality of wave numbers in each spectral data set serve as variables, to calculate the scores of a plurality of principal components for each individual sample;

a grouped-map creating unit for dividing the points on the specimen surface into a plurality of groups on the basis of the scores of a plurality of principal components calculated in the principal-component calculating unit and, on the basis of this grouping, creating a two-dimensional or three-dimensional grouped map that indicates to which group each point on the specimen surface belongs; and

a display device for displaying the grouped map.