Reshape data frame for choropleths plotting

Dear All,

I have a dataframe as below:

*name surname    year      sex    city1      city2     city3 *

*AA        AAA       2011    male     10        20         30*

*BB        BBB       2011    female   25        15         25*

*CC       CCC        2012    male      16      54          32*

*DD       DDD        2012    female    65      41          35*



I have in my* ui. R* two selectInput controls:

*  sidebarPanel(*

*    selectInput('year', 'Year, choices= data$year),*
*    selectInput('gender', 'Gender', choices= data$sex)*
*  )*


where I want to put my selected values



In my *server. R* I have a reactive function :



*  data <- reactive({*
*    a <- subset(data, data$year %in% input$year)*
*    a <- subset(data, data$gender %in% input$gender)*
*    return(a)*
*  })*


and what I want is dataframe* a* to be of form :


*name   city       freq*

*AA       city1       10*

*AA      city2         20*

AA      city3          30


and this data to connect with  existing .shp file with three columns:

*city    long     lat*

*city1   ....       ....*

*city2   ...          ...*

*city3  ....     ......*


in order to plot map with frequencies

Can you please help