 @testable import HDF5Kit
 
 class FileTests: XCTestCase {
-    let width = UInt64(100)
-    let height = UInt64(100)
+    let width = 100
+    let height = 100
     let datasetName = "MyData"
 
     func writeData(filePath: String, data: [Double]) {

        let filePath = tempFilePath()

        let file = createFile(filePath)
        let dims: [UInt64] = [width, height]
        let dataspace = Dataspace(dims: dims)
        XCTAssertEqual(dataspace.size, width * height)
        XCTAssertEqual(dataspace.dims, dims)

        let dataset = file.createDataset(datasetName, datatype: Datatype.createDouble(), dataspace: dataspace)
        XCTAssertNil(dataset.offset)

        }

        // Read as Float
        var actual = [Float](count: width*height, repeatedValue: 0.0)
        XCTAssert(dataset.readFloat(&actual))

        for i in 0..<expected.count {
