## How do you create a Biplot in Excel?

Creating a biplot

- Select a cell in the dataset.
- On the Analyse-it ribbon tab, in the Statistical Analyses group, click Multivariate > Biplot / Monoplot, and then click the plot type.
- In the Variables list, select the variables.
- Optional: To label the observations, select the Label points check box.

**What is Smartpca?**

smartpca runs Principal Components Analysis on input genotype data and outputs principal components (eigenvectors) and eigenvalues. The method assumes that samples are unrelated.

**How do you perform a PCA?**

How do you do a PCA?

- Standardize the range of continuous initial variables.
- Compute the covariance matrix to identify correlations.
- Compute the eigenvectors and eigenvalues of the covariance matrix to identify the principal components.
- Create a feature vector to decide which principal components to keep.

### What is Biplot analysis?

Biplot analysis is a graphical representation of multivariate data that plots information between the observations and variables in Cartesian coordinates.

**What is population stratification in GWAS?**

GWAS can be confounded by population stratification—systematic ancestry differences between cases and controls—which has previously been addressed by methods that infer genetic ancestry. GWAS have identified hundreds of common variants associated to disease risk or related traits1 (see Web Resources).

**How do I use XLSTAT in Excel?**

To use an XLSTAT function, you only need to type = followed by its name or you can use the Insert / Function menu of Excel, and then choose XLSTAT in the list on the left. Then select the XLSTAT function in the list on the right.

#### How do I add XLSTAT to Excel?

Enter “XLSTAT Cloud” in the search field to find XLSTAT Cloud in the office store. Once found, click on the Add button to install the application. After clicking the Continue button, the application automatically installs itself. Now click on XLSTAT Cloud shortcut in the Excel ribbon.

**How do I read data from a smartpca file?**

Here are my first two commands: where fn obviously should point to the *.evec.txt file produced from smartpca. The read.table command reads the data into a so called “DataFrame”, which is pretty much an ordinary table with some extra features.

**How do I set smartpca parameters in itamba?**

All the parameters that control a smartpca run need to be defined in a two-column text file. The name of the parameter is in the first column (followed by a colon “:”); the second column must contain the parameter value. Open the Itamba.par file.

## What is smartpca and how does it work?

The smartpca program uses a combination of Principal Component Analysis ( PCA; a standard statistical method) and new statistics designed specifically for genomic data to address this question. The methods are described in detail in an excellent and accessible manuscript by the authors of the program.

**How many SNPs are needed to project a PCA plot?**

This allows one to project even samples with as few as 10,000 SNPs into PCA plot (compare with ~600,000 SNPs for HO samples). So the first thing to decide is on the populations used to construct the PCA.

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