Workshop 3: Data Import

Importing data Normally, data to be imported into Excel work sheet are available as: - Excel work sheet file (.XLS) - Public source such as website - Data are saved in other file format i.e., text file (.TXT), and etc. If data are saved in.XLS files, we simply open and load them into work sheet. If data are publish in website, we can save webpage as.HTM files and import them into work sheet or simply cut and paste data from webpage into work sheet (if webpage allows us to do so). If data are available in other formats, we might have to try different techniques.

Importing data from web pages Use copy & paste technique Some web pages do not allow us to copy data directly Example:

Importing data from web pages

Importing data from file Data to be input into Excel worksheet might not always available in.XLS Some raw data produces by data acquisition equipment Many of them are simply text file containing only numbers and characters For example, climate data distributed by NOAA (US)

Importing data from file

Save this file in your computer.

Importing data from file This type of ASCII text file is usually found in your work To import data from text file into Excel, you have to guide Excel how the data are arrange in the file Data in text file can be put correctly in cell by specifying proper delimiter

Assigning name to data range When working with large set of data, normal reference to data range could be painful since it takes time to type, for example, A12:E87 It is better to refer to a specific range using name To assign name to data range, select the data range and then - go to main menu  Insert  Name…  Define - Type the name you prefer The data range can be referred to as its assigned name anywhere in work sheet

Basic statistical functions StatisticCell formula Count=COUNT(Data) Sum=SUM(Data) Mean=AVERAGE(Data) Median=MEDIAN(Data) Mode=MODE(Data) Standard Deviation=STDEV(Data) Sample Variance=VAR(Data) Standard Error=STDEV(Data)/SQRT(COUNT(Data)) Kurtosis=KURT(Data) Skewness=SKEW(Data) Minimum=MIN(Data) Maximum=MAX(Data) Range=MAX(Data) - MIN(Data) Largest(k th )=LARGE(Data, k) Smallest(k th )=SMALL(Data, k) Confidence Level(95.0%)=CONFIDENCE(0.05,STDEV(Data),COUNT(Data))

Basic statistical functions Exercise 1) From precipitation data, calculate: Daily precipitation Average precipitation of the month Minimum and maximum precipitation of the month Number of rainy days in the month 2) From air quality data, calculate: Minimum, maximum, average, standard deviation, skewness of each parameters for all provinces